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 The Myriad Ways: Future timespaces are like throw away countries where you can have massive casualties, even of the main characters, and it doesn't matter because it hasn't happened yet and (maybe) never will.
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.
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, in full-on Sarcasm Mode, 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 im in the series as he's happy to kill hundreds if not thousands to achieve his ends.
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.
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 (Oncetwice ALL THE FUCKING TIME), Peter Petrelli, Adam Monroe/Kensei, and of course Sylar (I've lost count!), 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 who's 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 succesfully 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 vacilitates 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.
Billing Displacement: Averted. Not only are the main cast members always billed in strictly alphabetical order, Heroes (along with Charmed and Eastwick) is one of the few non-soaps to credit just the actors who appear in each episode, instead of running a standard cast list.
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.
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.
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".
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.
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.
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.
"Every creature cursed with awareness asks, 'Who are we? Why are we here?' Is it the Search for Self? Why do we dream? When will someone finally point out that RNA does not work this way? What happened to Caitlin? When will I ever shut up?"
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 in my opinion being when Claire wakes up on the autopsy table ("Holy sh-").
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.