Absentee Actor: Common in seasons 1, 2 and 4, but not so much 3 - unsurprisingly Hayden Panettiere appears in the most episodes, with 73 (admittedly this includes one episode where she only appears uncredited in stock footage - but Santiago Cabrera once only appeared in stock footage and he did get credited, so it counts); Jack Coleman comes a very close second with 72.
Accidental Murder: The tension between Peter and Isaac reaches a breaking point when Isaac fires his pistol at the doorway where Peter was standing. Unfortunately, he fatally shot Simone instead.
Sylar accidentally stabs his mother in the heart when he tries to wrestle a pair of scissors from her after she tried to stab him with it.
Luke Campbell mentioned that his dad was abusive and used to to burn him with cigarettes.
Achilles' Heel: Claire can regenerate her body, and is therefore invulnerable unless her brain stem is destroyed... Maybe...
Claire is arguably an aversion, though, as Sylar implies that he was incapable of killing her even when he desired it after copying her regeneration into himself, which means that not even decapitation would actually kill her.
Adults Are Useless: HRG suffers from this, especially in the first Volume. He repeatedly forbids Claire from doing something important to her, guaranteeing she will do exactly that. He is genuinely shocked and upset that his teenage daughter does the opposite of what he has ordered her on multiple occasions. It's generally because he's seen one of Isaac's paintings, but if he'd only tell her that, things would be smoother.
Affably Evil: Mr. Linderman. After spending most of Volume One as a sinister Ghost in charge of threatening Mooks, he turns out to be a kindly, grandfatherly old man who, in his time away from managing his criminal empire, enjoys cooking, healing cripples — and plotting nuclear holocausts. All to make the world a better place, of course.**
Also, Adam Monroe. I mean, he wants to wipe out humanity with a super virus - all for the greater good, mind you - but he seems like he'd be a fun guy to go out drinking with.
In fact, this seems to be a recurring theme throughout the series: that, despite the name, nobody is purely good or purely evil. Even the permanent villain of the series, Sylar ( well, permanent only until the end of volume 5), he's shown signs of affability throughout recent volumes. Same goes with former Company boss Bob Bishop, crazy puppeteer Eric Doyle, and power hungry carnival owner Samuel Sullivan.
All There in the Manual: There is quite a lot of supplemental material, and one of the best things about this series is the way it has happily adopted using online content as a storytelling medium. There was an ARG mentioned below, several online-exclusive miniseries, and an ongoing series of comics. The latter introduce new characters, establish the (usually sad) backstories of existing characters, set up new subplots, and, most importantly, enable you to actually see the characters use their special abilities. Many fans have argued that the writing in these comics is consistently better than that in the series proper!
All Your Powers Combined: Peter Petrelli, Sylar, Linda Tavara from the graphic novels, Arthur Petrelli, and Samson Gray.
Variation: Samuel Sullivan's earth-manipulating powers grow stronger while more supers are near him.
Alone with the Psycho: Sylar and... well, anyone really. He did it several times with the Bennets and the third time actually succeeds in getting Claire's power. And back in the first season, Mohinder visits a powered human, unaware that the "Zane" he's speaking to is actually Sylar. The real Zane's body is stashed in the kitchen.
Always Save the Girl: Hiro trying to save Charlie twice despite warnings about his disrupting history.
In "Pass/Fail" this gets thrown back in Hiro's face, as Sylar rattles off a very shortened list of the people he's murdered since Hiro made a deal with him to save Charlie.
Amicably Divorced: Subverted here since Noah and Sandra Bennet seemed like such a strong couple, but they didn't seem to be able to get along much after their separation. Sandra even knew and supported Noah's edgy career choice while they where married.
They seem to tolerate each other well enough for the sake of Claire in the episode "Thanksgiving", but are generally not on speaking terms after their divorce. Especially since it's been heavily implied that it was an Arranged Marriage.
Anal Probing: In the seventh episode of Volume One, when Lyle discovers Claire's ability to heal herself after stumbling upon a tape that she and her friend Zach made to demonstrate her ability, this forces Claire and Zach to chase after him to retrieve the tape. A freaked out Lyle questions if they're both actually aliens to which Zach sarcastically responds, "Yeah, and we're gonna anal probe you."
And I Must Scream: Happens to Adam Monroe between Seasons 2 and 3 and Angela Petrelli at the end of "Angels and Monsters"
Anti-Villain: Adam Monroe and Samuel Sullivan. Especially Samuel, who seems to give a speech about the importance of family in every single episode, says Grace over every meal and gleefully talks about how good it is to "give back" to the earth by recycling. You don't get much more Anti-Villainish than that.
Samuel is basically Magneto only without the Holocaust backstory. All he really wants is to make sure that Evolved Humans are no longer seen as freaks by humans. It's just that he's willing to kill every one who gets in his way and the fact that he seems perfectly happy to slaughter large numbers of people to get his way that makes him a villain.
And let us not forget Mr. Linderman, who calls himself a "humanitarian" (not that way) and whose stated goal is to "heal the world."
However he seems to get over it by the point we meet him in the series as he's happy to kill hundreds if not thousands to achieve his ends.
Arbitrary Skepticism: People are extremely skeptical about Hiro's powers, even if they have powers themselves.
The most obvious example is Nathan Petrelli, who flies under his own power to escape a kidnapping — and then treats Hiro like a complete nutcase just minutes later.
Matt (a psychic) is equally skeptical in the dystopian future of "Five Years Gone":
Mohinder: Hiro Nakamura can stop time. Teleport by folding space. Theoretically, he can fold time as well. Matt: So you're saying he's a time traveler. Mohinder: Is that any stranger than being able to read someone's mind? (pause) Matt: Yeah. It is.
Arc Words: The stylised RNA symbol that appears on almost everything surrounding the Heroes (it's also a combination of Japanese characters saiyo meaning "great talent" or "godsend"), "Save the cheerleader, save the world," and the Activating Evolution book written by Mohinder's father, just to name a few.
Played straight with Noah Bennet, who wasn't even supposed to have a connection to Claire when they first shot the pilot.
Ascended Fanboy: Hiro goes back to the year 1671 in season 2 and meets his hero Takezo Kensei, and they go on adventures together.
The Atoner: Nathan goes through this in Volume 2, including getting tanked and growing an uber-scraggly Beard of Sorrow, over his role in nearly blowing up New York City in Volume 1. He goes back to being a dick midway through Volume 3 and through most of Volume 4, though, with pretty much the rest of the cast ending up as The Atoner in Volume 4.
Attempted Rape: Brody to Claire. Subverted, though, in that rather than being stopped by the Big Damn Heroes or even the girl herself, the attempt fails because he accidentally kills the girl, and apparently he's not a necrophiliac.
Author Appeal: Compare the sheer amount of blonde women against those with any other hair colour.
Also, check the heights of the majority of the main women. One would think Masi Oka had a line in his contract stating that all women who appear on screen with him must still be shorter even when wearing heels.
Making it surprising that he and the notably height-challenged Hayden Panettiere took so long to appear together.
Author Existence Failure: In-universe with Isaac. Subverted in that it doesn't seem to stop him. Even after he died characters have found and followed eight unfulfilled paintings, a year's worth of comic issues, and one of his sketchbooks. The same can be said for Mohinder's father and his writings.
Awesomeness by Analysis: Sylar's original power, Intuitive Aptitude, that allows him copy the superpowers of others... oh, and to repair watches (by intuitively figuring out how things work or where they're broken, which makes him a candidate for Cut Lex Luthor a Check). Also, Monica can do this with Muggle skills (Muscle Memory).
Axe Crazy: Sylar and, to a comparatively lesser extent, Elle.
Back from the Dead: Claire (ALL THE FUCKING TIME), Peter Petrelli, Adam Monroe/Kensei, and of course Sylar (see Claire), all thanks to the secondary Disney Death powers of their regeneration. Mr. Bennet and Maya, thanks to Claire's blood, as well as Nathan, thanks to Adam's blood. Linderman was teased to be this in Volume Three, but ultimately he wasn't.
Badass Family: The Bennets. Noah sets the gold standard for Badass on the show. Claire Took a Level in Badass in Volume Three, and single-handedly let the heroes loose in Volume Four. Sandra helps Claire hunt down villains in Volume Three and hide fugitive heroes in Volume Four. And even Lyle tries to brain the radioactive Ted Sprague with a baseball bat and even gets to take down Psycho Electro Elle in Volume 3.
In Volume Five, Big Bad Samuel wears a grunge version of one. Edgar wears one too, in the Season Finale.
Badass Normal: Mr. Bennet. And arguably Peter during the "Find the Haitian" thing. Unfortunately, in Peter's case, it didn't take. The Golden Boy is back to power mimicry thanks to the super-serum, though it's apparently a bit more limited. (Also, that would imply Peter had ever deserved the label badass). And as of Volume 4, it seems Hiro might be going this way too. He's certainly giving it his all.
Danko? I mean he throws a knife into Sylar's head. Pretty badass.
Badass Adorable: Hiro, while still retaining an almost childlike innocence. Claire and Molly have the adorable part down cold, just not the badass part.
Claire arguably becomes more badass as the series progresses, and is unarguably still adorable. (Even when taking a pencil and going all Rachel McAdams in Red Eye on Sylar.)
Bad Future: Once a season. (Note: Season, not Volume.) In a possible example of You Can't Fight Fate, pretty early in Volume Four it becomes clear that the Volume One Bad Future is turning into the Bad Present.
Likewise, Volume Five offers hints that Samuel may have played a hand in Volume Three's Bad Future.
Bad Powers, Bad People Both subverted and played straight — with Walking Wastelands Ted (and those that copied his power) and Maya, the blackhole-producing Stephen Canfield, and Sylar whose power comes prepackaged with a compulsion to take things (and people) apart to see how they work.
A few episodes of volume 4 and the webisode "Nowhereman" indicate the same is true of creepy puppetmaster Eric Doyle.
With the Webisode series over we've seen that Doyle, while not pure evil as he first appeared, is far from a hero. Even when he does good things he does them in a bad way and he's creepy as hell while he does it.
With Volume 5 he's back to being evil and working for Samuel in a plan to kill god knows how many innocent people
Beethoven Was an Alien Spy: According to the online graphic novels, Benjamin Franklin had the ability to absorb electricity, which is how he survived his famed kite experiment.
Berserk Button: If someone you had never met in your life that has no impact on your life and that might have only had one thing even slightly in common with you were to be killed, would you make a big deal out of it? Maybe not, but Samuel sure would. Oh yes, he sure would.
Beware The Cute Ones: Peter almost going all explody, Claire threatening Elle, Hiro's punishment of Kensei, and so on. Micah, the seemingly harmless kid genius managed to mastermind a huge underground resistance network that successfully fought back against a man with government funding and resources and a team of highly trained killers on his side.
Mr. Linderman seemed to have emerged as the one true villain of Volume One, though Mr. Bennet and Sylar gave him one hell of a fight for the title for a while. Also, at the end of the first Volume, numerous mentions of Molly's "Nightmare Man" inspired many to believe that whoever it was would be the Big Bad for Volume Two. It was Matt's dad, an original member of the Company. However, he was quickly and easily dispatched in early episodes.
In Volume Two, it is revealed that Adam Monroe, aka Takezo Kensei, is behind the deaths of the original members of the Company, and had a lot more than that in the works.
In Volume Three, it was Papa Petrelli pulling the strings, although (appropriate to the title, "Villains") everyone and their mother tried to get in on the act at first.
In Volume Four, the governmental anti-super conspiracy took the role from the start. For a while, it seemed like Nathan would play the figurehead, but he was quickly usurped by Danko, who in turn gets usurped in a last minute steal by Sylar.
Tracy looked all set to be this for Volume 5 from an end-of-episode teaser, but then comes Samuel.
Big Good: Angela Petrelli in Volume 3; Rebel in Volume 4.
Richard Drucker, an opponent of the Company, served this role in the Season 2 graphic novels plotline, but had no role in the main show's plot and appeared to be killed by the Company after a couple of appearances. The Volume 4 graphic novels show that Rebel was inspired partially by Drucker's legacy, though.
Big "NO!": Several times, but most notably HRG in Volume One after Sylar locks him up in a cell and sets on his way to Claire. Also Angela Petrelli after seeing Nathan dead in the Volume 4 finale.
Big Ol' Eyebrows: Nathan Petrelli, whose signature thick brows have been affectionately named 'Pasbrows' by the fandom.
This also goes for Sylar, complete with his own affectionate nickname, Sexy Brows 'Sybrows.'
The Petrellis. Dear God, the Petrellis. It's complicated of course.
Daddy was just this side of a psychopath, and was poisoned into near death by his wife.
Mommy is a cold blooded Manipulative Bitch who vacillates wildly from genuine affection for her sons to using them as tools for whatever purpose she needs.
Nathan will do whatever Angela tells him such as allowing New York to blow up, no matter what his personal feelings.
Peter, despite being the only one who'll stand up to her even momentarily, usually gets talked into going along with her.
Not to forget fringe members of the Petrelli family, Alice Shaw or more correctly the crazy aunt who spent 50 years hiding in desert soley because her sister (Angela) told her to wait for her.
The Bennets. Sandra seems better able to cope, but it's a miracle Lyle isn't in therapy with all the weird crap going on around him.
Not to forget the Grays. Sylar who kills a lot of people including his mother, Virginia (Sylar's mother) who isn't all there in the head and the psycho bio-dad who probably killed just as many people as Sylar including Sylar's mother in front of him as a child, after selling Sylar to previously mentioned crazy snow-glob lady.
Black and Gray Morality: The only hero who hasn't done any morally grey activity is Molly, and she is ten years old. Even Micah, who is about the same age, used his ability to rob an ATM and commit electoral fraud. And as the series progressed, all the adults have become darker. Which makes you wonder why the show is called "Heroes."
Black and Gray is especially apt. The prevailing moral philosophy seems to be that there is no such thing as good, only innocence/naivety. Everything else is varying degrees of evil, and the sooner a character embraces evil, the happier and more successful they will be.
Elle does this to Sylar by unleashing a powerful blast of electricity when he attempted to cut her head open.
Body Horror: Sylar fell all over himself to get a new shapeshifting power, without realizing it had a few side-effects... like extra teeth, uncontrollable shifting, and mental instability because The Mind Is a Plaything of the Body. And let us not forget Mohinder's "Let's experiment on myself!" adventure. Scales, goo, and cocoons, oh my!
Book Ends: Claire's Establishing Character Moment of her being filmed jumping off a large height in the pilot also closes out the series as she reveals her regeneration to the world by jumping off a Ferris Wheel on live television.
In the climactic scene of Volume 1, Sylar smirks "Tonight, I get to be the hero." In the climactic scene of Volume 5, he tells Doyle "I'm not like you. I'm a hero."
Hiro Nakamura, of course. It helps that he's the only one to really revel in his powers. Audiences reacted well to him, and writers responded by giving him an increased role.
Sylar definitely qualifies for this on so many counts. Initially supposed to be just the Book 1 villain, his popularity led to him returning endlessly.
Claire eventually went from a Damsel in Distress to being pretty much the face of the franchise.
Break the Cutie: The reason Elle is a sociopath is because her father decided to take his little girl and see just how much torture it would take to break her.
The entire series can be considered this for Claire. The season 4 villain outright states this is his plan for her.
Break The Gamebreaker: The most egregious being Volume Three's "Woah, wait, Hiro will just go through time and fix things! I will erase his memory and make him think he is a little kid again! Bwahaha!"
Brick Joke: A relatively quick version occurs in "Pass/Fail". Hiro's stuck in a trial being put on in his mind to determine whether he deserves to live or die. At one point, Sylar goes up to the stand and lists off all the people he killed because Hiro let him live after saving Charlie. He gets to Ted's name, but can't seem to remember his last name. Adam Monroe, leading the trial against Hiro, goes on to make a speech. A few minutes in, Sylar finally remembers the name, randomly shouting out "Sprague! Ted Sprague!".
Bring My Red Jacket: Claire, the castmember most likely to end up covered in blood due to her Healing Factor, wears a red cheerleading uniform for much of the first season. She manages to subvert Little Dead Riding Hood, despite constantly wearing red and having golden hair. After the first half of the first season, she almost never wears red again.
Brought Down to Normal: In Volume Three, Peter, of all people. But it seems to have done a lot for his God-Mode Sue problems. And everyone during "The Eclipse" episodes. And Hiro, temporarily as well, in Volume One and at the end of Volume 3.
Bullying a Dragon: Snobbery directed at the Big Badthat can level your housetends to be a suicidal idea. And apparently, Edgar has learned this lesson well. He starts a feud with Sylar, despite the latter apparently having quite a reputation amongst the superpowered community as an unstoppable brain-stealing murder machine. Granted, Edgar is Darth Maul and Sylar was a mild-mannered amnesiac at the time, but it still seemed like he was just asking for trouble.
Butterfly of Doom: Overused as an analogy in Volume Three. It's even worse in Volume Five - so much so that the Big Bad is named after it.
Matt Parkman has to be the undisputed king of this.
When the show opens, he's a joke amongst his fellow officers due to his constant failure to pass the exams to move up from patrolman to police detective.
He uses his powers to find a little girl who was the sole survivor of an attack by Sylar...and is immediately arrested on suspicion of being Sylar.
His telepathy reveals that his wife was cheating on him with his partner and - after they've reconciled in Volume 5 - it appears that she may have resumed doing so, but he can't confirm it because of his promise to stop using his powers.
He acquired a new superpower to see the future but nothing ever came of it save his having a lot of horrific visions and seeing his true soul mate.
Said soul mate then got killed before she and Matt could get married.
He was set up to look like a terrorist by Danko and a murderer by Sylar.
He lost his job at least once in every single volume.
He's the only character to defeat Sylar for good (twice!) only to have Idiot Hero Peter undo it (twice!!!)
Niki Sanders is a close second. If Matt Parkman was the King of the Butt Monkeys on this show, then Niki was their Queen.
She's stuck working a humiliating job as a web-cam girl to pay for her prodigy son's schooling and to pay back the gangster who she borrowed the money from in the first place.
Her powers caused her to develop MPD, with her two most dominant personalities being a self-serving murderous Black Widow and the other being a vapid party girl.
She committed herself to try and stop her murderous personality from killing her husband, only to wind up getting abused by the guards there and - ultimately - being unable to free herself from the influence of the gangster that was blackmailing her.
The later of her personalities indirectly caused the death of her husband, D.L.
Ted Sprague, whose radiation emitting powers caused him to unknowingly give his wife cancer, be hunted as a terrorist and finally get killed by Sylar certainly qualifies.
Maya, who killed her entire village save for her brother and countless other innocents also qualifies. Ironically, she's one of the few supporting characters that gets a relatively happy ending as she lost her power and is given the opportunity to lead a normal life.
Cain and Abel: Peter and Nathan in the Volume Three season finale.
The Petrelli brothers subvert this trope in Season 1 - twice! First, in "Five Years Gone", and then in the season finale.
Call Back: Brought up in-universe in Season 3 when Peter hails a cab and it turns out to be Mohinder is the driver. They proceed to quote their very first meeting from the pilot and then grin at each other before discussing more serious matters.
Calling the Old Man Out: Nathan and Angela; Matt and his father; Claire and Mr. Bennet; Nathan and Arthur; Sylar and Samson.
The Cameo: Several, but we especially loved Stan Lee's awesome appearance as a bus driver in "Unexpected" and Seth Green in "The Eclipse".
Cannot Spit It Out: The show would probably be 40% shorter if characters actually shared basic, critical information with each other.
Canon Discontinuity: There was a lot of bad ideas introduced in Volume Two and Three. Volume Four spent a lot of time undoing the ones that could be undone, and the remaining ones... well, they're just not mentioned anymore. Ever.
There's a few minor points in Season One as well, the most obvious being the issue of Mohinder's birth (first he was born before his sister died, then after).
Can't Hold His Liquor: Oh, Nathan. You think you're so tough but you're an embarrassment to drinkers everywhere. The fandom will laugh forever at the tequila scene in "Into Asylum".
To be fair, he's been seen drinking heavily before and was fine. He did claim that he was a pro at drinking contest during his days at the Naval Academy...it's really more like he's just about 20 years out of practice.
Averted in the same episode by Claire, who has to pretend she can't hold her liquor since she can't get drunk.
Cape Busters: Nathan and Danko's team of Black Ops soldiers in Volume 4, who are attempting to capture and detain every evolved human in the United States because their powers are too dangerous. Yes, even the lame ones. Except Sylar.
Car Cushion: One of Isaac's paintings show Peter lying on top of a crushed taxi. It turns out that Claude pushed him off a building and he crashed into the taxi. He survived, thanks to having Claire's regeneration, but was royally pissed off.
Car Fu: Claire's revenge against Brody is to crash his car at full speed straight into a wall. The accident left him paralyzed.
Card-Carrying Villain: Knox in Volume 3, mainly because his Start of Darkness backstory got cut from the Volume 3 flashback episode. It is still available online and on the Season 3 DVD, however.
Cast from Hit Points: Hiro gets a weakened version of his power back from Baby Touch And Go's power, only to find out that every time he uses it takes a toll on his body and brain and is slowly killing him. This has been retconned to the power itself taking a toll on the body, as Samuel's time-traveling buddy Arnold demonstrates.
Chaste Hero: Past-Noah manages to refuse the advances of a beautiful woman who he was working with at the time.
Cheek Copy: A former Yamagato employee considers suicide after being fired for drunkenly doing this at an office party. As Hiro tries to prevent from him doing this by going back in time, each time results in the same thing at different times. After 47 times, Hiro finally gives up and talks to the man.
Half-way through Season 1, Nathan teaches Hiro the correct pronunciation of "villain". Ten episodes later, Hiro is using the word to great effect - on Nathan.
The last 9th Wonders comic book is needed for a Plot Coupon in Volume Three. Unfortunately, the author... well you know. But wait! He gave his sketchbook to an anonymous bike messenger back in Volume One...
At the beginning of the series, Angela gets busted by the police for shoplifting socks, which perplexes her sons and seems out of character for her, especially as the audience gets to know her better. In the Volume Four episode "1961", the reason is finally revealed: whenever Angela feels lost, she steals socks to remind herself of her sister, her goals, and her purpose (It Makes Sense in Context).
In the third episode of Season 3, during Angela Petrelli's reign of babymomma-ing Sylar, the superpowered serial killer was given the ability of clairsentience by a hapless mook. Didn't seem to do much until the middle of Volume 4, when Sylar learns the fate of his true parents in the dilapidated cafe, and even further still in Volume 5, when Angela gives him a box of Nathan's belongings (as Sylar has shapeshifted into Nathan) which triggers "Nathan's" memories of a young girl's murder back when he was a teen.
Cliffhanger Copout: A number of cliffhangers would pique viewers' interest that one thing would happen and then would give them something entirely different at the start of the next episode. The episode "Truth & Consequences" from Volume 2, for example, ends with Hiro charging at Peter, who refuses to believe Hiro's claims that Adam Monroe is dangerous and is even willing to protect him, suggesting that the two characters were going to fight each other. The beginning of the following episode, "Powerless," shows Hiro, after his charge, deciding to just teleport around Peter and try and talk to him some more to convince him that Adam is evil.
Coconut Superpowers: The show that inspired the trope. Fortunately, the budget seems to finally allow for more "showboating" beginning in Volume Three.
Code Name: The Haitian was only finally referred to by his real name in Volume 5.(It's René)
Notable in that suddenly EVERYONE who's ever met him, even briefly, know who he is, despite always referring to him as the Haitian before that point.
Coitus Ensues: Sylar and Elle randomly getting it on towards the end of volume 3.
Which suggests that the Volume 3 Bad Future has not been averted...
Or at least heavily implies that Samuel may have been the cause since his power in amplified by the presence of other Specials and the Volume 3 future had powers readily available to the public via the induction serum.
Cosmic Deadline: Most notable during volume one (season one) and volume two (season two). For the former volume, even with a twenty-three episode story arc, the last three episodes's pacing noticeably sped up to the point of distraction. Events fell together quicker than usual, Idiot Ball after Idiot Ball got tossed around to make the characters move around improbably fast, and even the long awaited final confrontation teased over the course of the season ended far too fast. Tim Kring stated that the production end ran out of time and money to let the plot properly develop, but sought to avoid such scenarios for the next season. Alas, that didn't quite happen, thanks to the writer's strike affecting production, which forced the creators to avert their initial plans.
Couldn't Find a Pen: Sylar painting the future in his mother's blood. Sylar cutting his name into his forearm while he was having his shapeshifting identity crisis. Sylar also leaves a note on the wall: "Sylar was here" in his victim's blood also during the identity crisis.
Happens to Nathan/Sylar twice in a single episode. Sorta.
Cult: The Sullivan Bros. Carnival is run like one, complete with references to "the family," religious trappings, isolation, physical labor for no pay, and, of course, a charismatic leader with self-proclaimed prophetic abilities (which, unlike in real life, happen to be real).
Curse Cut Short: Plenty, the best for many people being when Claire wakes up on the autopsy table...
Claire: Holy sh— *smash cut to black screen and TO BE CONTINUED...
Hiro...YOU SON OF A BI....
Cursed with Awesome: Claire's healing powers, whilst meaning she'll have a long life, mean she can't get drunk!
Cut Short: The final scene sets up a Season 5 (Volume 6). But the low ratings made NBC think otherwise.
Destructive Romance: Sylar and Elle. They honestly loved each other but are far too messed up in the head. Sylar ends up killing her because Bennet's word made him give up on himself and believe that there was no way they could have a happy ending.
Deus Exit Machina: The Haitian, whose power is to block other people's powers. Although he is the one person who could actually kick Sylar's ass rather easily, he is never seldom around when needed.
Similarly, Matt Parkman is kept well away from the climactic battles in Volumes Three, Four, and Five, since his burgeoning Psychic Powers would allow him to just make the bad guys surrender (or worse, if he were in a bad mood).
Differently Powered Individual: The show generally avoids using a general term for its supers, and they are mainly referred to vaguely as "people like me" by those with powers or "individuals with abilities" by those without. The Company seems to officially refer to them as "specials", although this was mostly in the online comics. Adam also used the term "specials" to describe powered humans. Danko started using the term too, so it seems to have become the show's "official" word for people with powers. The general fan consensus seems to refer to them as "evolved humans", so much so that even NBC's publicity department uses the term.
Discard and Draw: Peter lost his ability in Volume 3, and regained a weakened version — the ability to copy the power of the last person he touched—at the end of the season. This does wonders for his intelligence, as the writers no longer need to glue the Idiot Ball to his hands to stop him being a gamebreaker.
Disc One Final Boss: Mr. Bennet to Mr. Linderman in Volume One, Nathan Petrelli to Emile Danko in Volume Four.
Disproportionate Retribution: Samuel goes to New York City and decides to visit the mansion where he lived as a boy, and asks to have a look around. The new owner, with some condescension, turn him down since they're in the middle of a fancy dinner party, and then everyone in the house laughs when he returns. So he destroys the whole place by creating a massive sinkhole underneath it, killing three of the party-goers in the process.
And then he wipes out an entire town and kills hundreds because Vanessa refuses to be with him and a waitress asks him what's wrong.
There's also the fact that he had the Caimen Police Department demolished with the police still inside because the deputy and several of his men had a kid who determines life and death dragged to death as a lynch execution.
Dork Age: Actually seen in-universe. Several characters who were last seen attempting to kill each other in Volume 3 meet again in the first episode of Volume 4 and act quite civil towards each other, with the apparent unspoken agreement to pretend that Volume 3 never happened.
Double Vision: Peter interacts with himself from the exposed ability future. Hiro does this twice with both the past version and an alternate future terrorist version of himself.
Peter is all set to try this after knocking out one of the Black Ops agents, until Tracy points out to him what a stupid idea it is. They still put on the uniforms anyway because the orange jumpsuits give them away as fugitives and why say no to free Kevlar?
Sylar sneaks up on Danko like this.
Danko: "How the hell did you get in here?" Sylar: "Well, you’d be amazed what you can do with a lifted I.D. badge, a four-dollar tie, and a West Baltimore accent."
Hiro also does this when he and Ando try to shut down building 26.
Drinking Contest: Claire and Nathan flee to Mexico and in order to get some money to return home, participate in one. Despite Nathan's claims that he's been a pro at this since his Navy days, he's knocked out early in the contest and Claire has to fake her way through in order to get the money.
Dropped a Bridge on Him: Simone, DL, Caitlin, Adam Monroe, Bob, Usutu — though he got better, maybe — Scott, Knox, Nathan...
Danko. He survives the entirety of Volume 4, despite the fact that every single person wants him dead. He is back for Volume 5, and he is building up to retaining his recurring character status. He even narrowly avoided death at the hands of Tracy. Not even a minute later, Knife Guy comes in and slices him up, killing him before he even knows what's going on.
DL was probably the worst example. Everyone else was killed onscreen. DL was shown dead with no explanation until the 8th episode of the season and the way he was killed by someone with no powers (who is not Bennet) just seemed like an excuse to get rid of him.
Both Hiro (unsurprisingly) and Peter Petrelli (even more unsurprisingly given his carriage of the Idiot Ball throughout Volume Two) fall under this effect.
In Volume Three, Matt is fawning over a thief with Super Speed he just met yesterday, all because he had a psychic vision of them being married in the future.
Hilariously subverted by Hiro during his introduction to Daphne. Rather than assume she's a complex human being with a complex motivations, he likens Ando and he to Batman and Robin and then refuses to refer to her as anything but "Nemesis" or "Catwoman" afterwards. He quite literally gets too caught up in assuming she's evil to make any sort of judgement call on her.
Empty Fridge Empty Life: In Season 4, it's shown that after Noah and Sandra divorced, his apartment's fridge is constantly empty and he eats cereal because there was nothing left and he's burnt his other food. Claire regularly helps him out until Lauren re-enters his life.
In a variation, Peter's fridge is also shown to be rather empty in Season 4, but this is because he's such a workaholic that he forgets to buy groceries.
Part of Volume Three had Noah Bennet and Sylar teaming up. It didn't work out so well.
The Volume Three finale, where Bennet frees all the Level 5 supervillains to help fight Sylar. They all last about 3 minutes, tops.
Sylar is pretty damn good at getting mortal enemies to drop their differences in order to team up and stop him from Taking Over The World (of course.) The Season 1 finale basically had all the desperate characters coming together to put the smack down on Sylar before he could nuke New York to become President of the United States. Though granted, that was shown to be a future result of the nuke and not his actual motivation. And, in the Volume 4 finale, Bennet and Danko team up to stop Sylar from (again) becoming President of the United States... which lasts for about 5 minutes, until Danko decides to backstab Bennet just for the hell of it.
Used in the Volume 5 opener, when Bennet and Tracy quasi-team up to get Danko off her case - resulting in Danko being swiss-cheesed by Edgar five seconds later.
In a twist, as of Volume 5, Sylar and Peter seem to have teamed up, though Sylar is trying to be good again. It seems like it might take.
Being trapped for five years in your own mind to wallow in your guilt will drastically change one's outlook on life, especially if you're only company is your more compassionate and moral archnemesis.
Everybody Lives: In the "Redemption" season finale, the Heroes manage to stop Samuel's plot to destroy New York City without causing or allowing a single death; thanks to Big Bad Samuel's many Kick the Dog moments throughout the season, his right-hand men and other followers are all convinced to turn against him without a fight, rendering the previously all-powerful Big Bad into a powerless sap to be dragged off by the cops. Meanwhile, Sylar stay true to his redemption and incapacitates Doyle without killing him. This is pretty noteworthy considering the show's tendency to purge all its secondary characters at the end of each Volume, typically with a massive Sylar-centric bloodbath.
Everyone Loves Blondes: It's been referenced several times that Nathan likes blondes. His exes Meredith and Tracy are both blonde. Claire is also blonde, which makes the reveal that she's Nathan's daughter with Meredith all the more effective.
Noah and Sandra are also blonde, and after their divorce, their new significant others are also blonde.
Everyone Went to School Together: A variant. Angela Petrelli, Charles Deveaux, Daniel Linderman, and Bob Bishop, as well as Angela's younger sister Alice spent time at Coyote Sands, a relocation camp for people with abilities, where Chandra Suresh was also a doctor.
Evil-Detecting Dog: Zig-zagged with Mr. Muggles. Most of the time he can tell when something is wrong, but he seemed to not have a problem with a disguised Sylar and Revenge!Ted.
A deleted scene from "The Second Coming" plays this straight when Sylar has trapped Claire inside a closet and Mr. Muggles goes mad barking at him. He gets flicked out the doggie door for his trouble.
Except that in Sylar's case, once he started donning the hair gel, he kept trying to go good.
Evil Is Not a Toy: Whenever some erstwhile Chessmaster keeps Sylar alive or even feeds him powers while plotting to use him to further their own evil schemes, you know the main man is going to eventually turn around and make things end badly for them. Bennet even Lampshades this when confronting Danko.
Bennet: Just how dumb are you? Who did you think would be left standing the moment Sylar got bored? You?
Evil Overlooker: Both covers to the first graphic novel collection show Sylar looming over the Heroes. As does the Season 2 DVD cover. And the second graphic novel collection.
Evil Overlord: Arthur Petrelli fits pretty much every item in the checklist.
Evil Versus Evil: Volume Three looked like it was working towards a battle between Primatech Paper/The Company (a morally ambiguous Ancient Conspiracy that tried to blow up New York City to unify the world) and Pinehearst Industries (a Legion of Doom of supervillains whose actions are apparently destined to make the world explode). Yeah...
Expecting Someone Taller: After meeting him in Volume 5, Samuel and Lydia discuss their disappoint that the long feared, Shrouded in Myth figure of "Sylar, the most powerful one of all" turns out to be a confused amnesiac with a rather mild-mannered disposition.
There's a reason for his nicer attitude - the memories he's retained are still Nathan's.
Exposition of Immortality: We first encounter Adam Monroe through Hiro travelling back in time to 17th Century Japan. When we next meet him, it's the 21st Century and he looks exactly the same. It's explained directly to Peter that Adam's cellular regeneration power keeps him alive and stops him from aging.
Extra-Strength Masquerade: From nuclear explosions over New York City to people using their powers to cheat in Vegas casinos, from a Serial Killer who freezes his victims and cuts their heads open without a blade to a concentration camp for metahumans constructed in The Sixties, and from former employees of the Mutant Draft Board putting their experience on their résumés and being hired by the CIA to an effort to abduct American citizens with superpowers being discussed (albeit in vague terms) on a Captain Ersatz for the Larry King show, there should be no way that The Masquerade can endure...and yet it does.
Eye Scream: Inflicted on Sylar by Claire in "Pass/Fail".