The Invisible Woman (Susan "Sue" Richards [née Storm]), who originally could only become invisible, she later developed special force field powers, and these have arguably been her defining ability ever since.
Action Girl: Invisible Woman, and there have been two female stand-ins for Ben Grimm: She-Hulk, and Sharon Ventura, who was transformed into a Distaff Counterpart of The Thing. Crystal of the Inhumans also once filled in for Sue. So did Medusa, Crystal's sister.
Action Mom: Invisible Woman, mother of two and still telekinetic butt-kicker supreme.
Alternate Universe: Many, many of them. The FF have the highest number of canon AU stories. And whenever they needed to be avoided from a crossover; their absence is usually handwaved with: "The FF are away in an alternate dimension..." At one point, it's even revealed that Reed Richards often holds trans dimensional conferences with numerous alternate versions of himself at the same time.
Ambiguously Jewish: Benjamin Jacob Grimm, until it became canon a few years back; and he undertook a second Bar Mitzvah to commemorate the occasion of his 13th Anniversary of turning into The Thing. His very look is loosely inspired by the Jewish folktale of the Golem.
Anyone Can Die: The focus of the Three storyline. It was Johnny — but of course he got better.
Artifact Title: Membership changes and flash-forwards often show the "Four" in the team's name ends up an artifact title, with various continuities including HERBIE, Kristoff von Doom, She-Hulk, and Franklin and Valeria Richards as official team-members. This was especially noticeable at the end of the "Fantastic Five" Flash Forward series where the team expanded at the end to include eight members.
Badass Bookworm: Reed Richards happens to be not only elastic, but the biggest nerd on Earth.
Ben Grimm should also qualify, at least by implication. They don't let Book Dumb bruisers become test pilots and astronauts (in Real Life you have to have at least two Master's degrees or a PhD to be considered for space missions), and apparently Reed found him qualified to fly an experimental spacecraft. He also can follow Reed's Technobabble well enough to translate it into Layman's Terms,
Breaking the Fourth Wall: A memorable moment in Issue #10, from a series not known for breaking the fourth wall on a regular basis. Stan Lee and Jack Kirby, struggling to write a plot for that issue, reflect on the mistake of sending Doctor Doom into space. Then, almost as if on queue, Doom barges in to their office and threatens the pair to call Mr. Fantastic to "discuss a new plot". Then, at that moment, Johnny answers the phone, telling Reed that it is Lee and Kirby, wanting to discuss a new plot, to which Richards questions it, stating that they just discussed working on a plot the previous day.
Broke Episode: Issue #9, and the first 12 issues of their Marvel Knights series.
Comic Book Time: Perhaps more visibly in force here than in any other comic. Franklin was born in 1968, and has yet to reach puberty despite the fact that he really ought to be older than many, many Marvel Comics characters that are older than him despite having been born decades later.
Detachment Combat: The Fantasti-car separates into four smaller vehicles for each of its passengers.
Determinator: The Thing. The Champion declared him Earth's greatest hero, because even if he's not the most powerful, he will not yield.
Did You Just Punch Out Cthulhu?: The FF probably has more moments like this than anyone else in the Marvel Universe, but one of the most notable examples was when Sue killed (or at least disincorporated) a Celestial (thanks to some handy advice from Uatu).
Disproportionate Retribution: Considering that Reed had absolutely nothing to do with Doom's experiment failure or his injuries, Doom's grudge is completely unwarranted in the first place; but the sheer lengths that Doom goes to in his search for vengeance frequently go way beyond 'excessive'.
What's amazing is Doctor Doom's quest for revenge is often as petty as it is insanely over the top. For instance, he's actually tried to break up Reed Richards' marriage as often as kill him.
Elemental Baggage: For Johnny's power source in creating flame. Occasionally justified by him feeling tired or very hungry after using extremely hot flames.
And then there's the part about his body and his powers both needing oxygen to function. There have been times when he's been trapped in airtight spaces, causing him to pass out when his flame powers used up all the oxygen.
The Thing's rocky exterior makes him incredibly heavy, to the point where he has to use an elevator by himself to avoid overcoming the max lift weight and everything meant to accommodate him has to be built very large and reinforced.
Notable when Reed's daughter Valeria brokered a deal with Doom. Doom will work with the Future Foundation to bring down a group of amoral alternate Reed Richards. In exchange they would heal his super-intelligence crippling brain damage. Doom upon being restored gathers a summit of the FF's most intelligent enemies to work on strategies to kill the Reeds. At the Foundation's headquarters.
Evil Detecting Baby: In one issue, Doctor Doom walks the streets of New York in civilian clothes (with a less ornate mask replacing his usual one). He passes a baby boy, who begins screaming and crying uncontrollably. Doom apologises to the boy's mother for frightening the child; the mother replies that the baby is blind.
Fakeout Escape: There's a sequence in Fantastic Four #2 where Sue turns invisible when government officials come to check on her, then runs out the doorway during their confusion; this was enough of an Establishing Character Moment that it gets repeated in both the Ultimate and filmed versions.
To say nothing of the rivalry between The Thing and The Hulk, which is born of equal parts hatred, admiration, and respect. Whenever they meet they refer to each other almost exclusively as "Grimm" and "Banner."
Game of Nerds: Reed Richards makes the occasional baseball analogy.
Heck, Ben had a baseball-nerd moment as well: he once realized he was in a slightly-different parallel universe when he read a newspaper and found that the local sports trivia didn't match the stats he'd carried around in his head.
Genius Bruiser/Gentle Giant: The ever-lovin', blue-eyed Thing, Ben Grimm, although his smarts are usually overshadowed by super-genius Reed. Ben lampshades this as he assembles a cosmic ray device, musing that he's watched Reed long enough to play Mad Scientist himself. There is also the fact that Grimm was a highly qualified test pilot before he became The Thing; no mean feat brain-wise.
The idea of The Thing being simultaneously physically strong, ugly, and smart was seen as revolutionary in comics.
Also, Infant Terrible, a Silver Age alien antagonist.
Guile Hero: Invisible Woman should be portrayed as this. She shamed Ben Grimm into piloting the ship during the first issue. She was also told to distract many of the Silver Age male supervillains. After Psycho Man temporarily turned her into Malice she used her knowledge of Reed and Psycho Man's personalities to track him down and take revenge on him. When Dr. Doom stole the power cosmic from the Silver Surfer, she tricked him into flying into a mountain. During the Civil War, she spied on Reed. As any real chessmaster/manipulative bastard/guile hero would tell you, the greatest achievements in theses tropes is to make certain that your opponents don't realize you are a social expert.
Valeria Richards is this too, especially when written by Jonathan Hickman. She seems to have inherited her dad's smarts - and her mom's wits.
Heroic Spirit: Thing saves the world once just from showing how he wouldn't give up.
A Hero To His Hometown: Doctor Doom, Gladiator and Mole Man all have good reasons to be hated by the outside world, yet are loved by their citizens
Hidden Depths: Johnny generally acts like a teenager on hormonal overdrive, but he's generally portrayed as a skilled mechanic at the very least, and a competent planner at his best.
As for the rest of the team: The Thing is likewise a very intelligent ex-fighter pilot. On his worst days, he's needy, pessimistic, and pushy; on his best, he is braver than Captain America. Sue is the most powerful member of her team and on her best day the Team Mom, but she's got self-esteem issues and doubts Reed's devotion to her and to the family. Most interesting of all is Reed: he's brilliant, he's rich, he's famous, he's got a great family and the name of every other superhero on his rolodex, and he's even easy on the eyes, but every so often he admits his deep guilt over causing the accident that made the Fantastic Four in the first place -— even guilt over what happened to Victor von Doom, even though he didn't have a damn thing to do with it.
Hidden Elf Village: The Fantastic Four discovered Attilan, a hidden city, which was the retreat of the Inhumans.
Valeria also tends to address Doctor Doom as "Uncle Doom", which he appears to actually like.
Hope Spot: During the early days of the series' run, Ben would periodically revert back to his old human self for a few minutes before turning back into The Thing again. Not only did this give Ben hope that the power of the cosmic rays were weakening on him, but it gave the rest of the four hope it might do the same for their powers.
Kirby Dots: Made their first appearance in the comic.
Large Ham: TREMBLE WITH FEAR BEFORE DOOM'S TITANIC MONOLOGUES!
Ben and Johnny tend to ham it up when they're bickering, particularly Johnny's fire-based pranks, Ben's threats that he hardly ever follows through with, and his endless fire-based insults (match-head, flame-brain, etc.)
IT'S CLOBBERIN' TIME!
Last Name Basis: The Thing seems to be on a permanent last-name basis with Bruce Banner (possibly having to do with his main rival being Bruce's alter-ego, and when he gets sufficiently pissed at Reed he'll start referring to him exclusively as "Richards."
Lawyer-Friendly Cameo: In the early days of the series, Stan Lee and Jack Kirby made an appearance, faces hidden from view, just to be bullied by Doctor Doom into altering that issue's plot in his favor.
Another time, Johnny purposely used a intentionally-crudely-drawn version of the first issue of "The Incredible Hulk" to rile Ben. Needless to say, it worked, and even before Ben could tear the issue up himself, Johnny accidentally burned it to cinders while trying to grab it.
Layman's Terms: Ben usually dumbs down the complex explanations Reed Richards comes up with for the people around him. When Reed starts speaking too Star-Trek even for him, it's also Ben who normally snaps at him to "Speak English, Stretcho!"
Legend Fades to Myth: In one arc, they come across a town suffering from Decade Inside Second Outside; inside the town the Fantastic Four are considered legendary heroes (even more so than in Earth-616 Real Life) and the inhabitants are quite upset when they find out about what they're really like.
Lightning Bruiser: The Thing is just as agile and well-trained in martial arts as he was before his transformation, lots of people forget that. Woe on them.
To quote Ben himself from an issue of Marvel Knights 4:
Here's a little-known fact people sometimes forget - for someone my size, I can move a lot faster than I should be able to.
Mama Bear: Sue to the rest of the team, especially to Franklin and Valeria.
Master of Disguise: Mr. Fantastic has infrequently used his stretching powers to assume a different face.
Monster Modesty: Even though the Thing has been horrified by his monstrous appearance, he often runs around in blue short-pants and nothing else.
Morally Ambiguous Doctorate: Dr. Doom never actually finished his doctorate, but he sounds scarier with a "Doctor" in front of his name. Reed Richards, who finished several doctorates, chooses to go by Mr. Fantastic.
Then again, it's (maybe) possible Victor'd already had at least one doctorate under his belt and was pursuing another one at the time of the accident that scarred him.
Or, perhaps when he took over Latveria he had one of its universities give him an honorary degree.
Or it doesn't matter. Even most doctors aren't smart enough to steal powers from cosmic beings.
Most Common Super Power: For a time during the mid-90s, the Invisible Woman wore a skimpy costume with a cut-out "4" on her cleavage. This was before writers and editors realized that they didn't have to dress Sue up in a slinky costume to make her sexy — she was already a MILF.
Mr. Exposition: In their early appearances the Inhumans come across as an entire race of these. This is partly because they have to speak for their mute leader Black Bolt, and partly because they would appear Once per Episode as part of a story arc and have to recap everything for casual readers.
The Nicknamer: Ben. Some of his nicknames include "Stretcho" for Reed, "Bic-head" and "Matchstick" for Johnny, "Suzie-Q" for Susan, "Jade-Jaws" for Hulk, etc.
Not So Different: Although they're on opposite ends of the good vs. evil thing, both Reed and Doom are insanely intelligent, somewhat condescending, and often only care about completing whatever task at hand will best benefit whatever, tossing aside everything else.
Not Wearing Tights: For the first two issues. They only started wearing them because of fan demand.
The Notable Numeral: The eponymous heroes and their enemies The Frightful Four, headed by the Wizard.
The One Who Made It Out: Ben Grimm is a former member of the Yancy Street Gang, and they resent him for forgetting his roots.
Pals With Jesus: All four are friends with Uatu The Watcher, one of the most powerful beings of this universe.
Even better: Galactus, a freakin' embodiment of a cosmic force, has said that the Fantastic Four are the only beings in the Universe that he can call his friends. In fact, in one issue we see an older version of Franklin promise Galactus that he'd be with him at the end of the universe. They share a moment floating above the Earth.
Personality Powers: Especially noticeable with the hot-headed Human Torch and the solid and stubborn Thing.
Also originally Sue was a shy, almost invisible to people woman and Reed had an elastic mind.
Justified via Retcon when it's revealed that their powers were, in fact, based on their personalities, as Reed gave them their powers during a Timey Wimey Ball.
In "What if the Fantastic Four had different super powers?" (What If v1 #6), Johnny became a robot due to his being a skilled mechanic, Ben became a Winged Humanoid with dragon-like wings for his passion about flying (on jets), Sue had elastic powers being a very conciliatory woman and Reed became a bodiless brain because of his peerless intelligence.
And then with the return of Johnny, "Fantastic Four" was relaunched & the team began using the name with redesigned FF uniforms; whilst the "FF" series began focusing on Franklin, Val & the rest of the kids at the Baxter Building.
With Marvel NOW, in "Fantastic Four" the Richards family are taking an intergalactic vacation for a year, whilst in "FF" Scott Lang, She-Hulk, Medusa and Johnny Storm's current girlfriend, Darla Deering, are recruited to serve as the heads of the Future Foundation & the Fantastic Four in the absence of the Richards family.
Status Quo Is God: The Thing gets turned into a human about once every few years, but always gets turned back, usually because he needs to help someone out.
It's something of a running gag. Sometimes when it happens he actively tries to regain his powers as he feels useless and naked without them.
In one story arc, Reed tried to remove Ben's mutation and add it to his own elasticity, but Ben refused to let him. "You're you an' I'm me, an' that's the cosmic plan."
Johnny dying a year before the FF's 50th anniversary. Yeaaaah, that'll stick.
All part of the plan - Johnny ends up in the Negative Zone leading a Five-Man Band to overthrow Annihilus and gains control over the Annihilation Wave.Took a Level in Badass indeed.
Story Breaker Power: Franklin is a major case of having this, which is why he can never be allowed to permanently grow up in-story. He also keeps having his powers nerfed after doing anything sufficiently cool. This is because his full power is well beyond most characters who are considered gods; perhaps the only Earthling who compares to him is Scarlet Witch (who also has her powers reined in by something or other most of the time.)
Stripperiffic: Unusual for a comic series in that the team's main female member only rarely falls under this trope, preferring a modest blue bodysuit identical to the ones Reed and Johnny wear, but it does happen - like when she wore this costume for a few years in the 1990s. The change was widely panned by fans and removed.
Sudden Humility: In one issue, Sue and Johnny swap powers. Sue constantly loses control over her new powers and notes how she constantly "Flames On!" by accident whenever she gets excited or emotional. She's utterly amazed that a Hot Blooded person like Johnny was able to keep this much power under control, and she gained a newfound respect and appreciation for her brother because of how difficult it was for her to remain in control at all times.
The Von Trope Family: Doctor Doom's real name is Victor Von Doom. Reed and Sue's daughter Valeria could also fit here, since in one alternate future she was Doctor Doom's daughter, but Sue was still her mom.
Weirdness Magnet: The Four tend to meet or attract various aliens, inter dimensional beings... whether intentional, or by accident.
By this point now he's pretty much over it, although he has his good days and his bad days.
The "bad days" that happen to him are usually caused by someone (most of the time a kid or kids) who're not used to seeing him up close get freaked out. Sometimes accompanied with a scream like "Mommy! It's a monster!" or some variation thereof, and he gets reminded of his hideous appearance. The real reason for this, however, is because True Art Is Angsty and writers sometimes want to do wangsty stories centered around him. For long-term fans who've followed FF stories through the years, it's getting a bit old.
What If?: Marvel's What If comic line does have stories of these kinds about the Fantastic Four, but most interesting is What If? Vol. 2 #11, which told four stories about the team all having the same power. These stories are designated in the Marvel Encyclopedia Vol. 6 as Earth-9031 (all flaming), Earth-9032 (all stretchy), Earth-9033 (all monsters), and Earth-9034 (all with invisibility powers).
What Kind of Lame Power Is Heart, Anyway?: Susan used to have only invisibility in the early stories until Lee and Kirby realized that it was next to useless compared to the male members' powers. As a result, they gave Susan her force field powers, but it was only later under John Byrne's period that she learned to really make it a kick ass power set, using it with a new aggressiveness in battle. Since then, different writers have her being considered not only the most powerful member of the team, but one of the most powerful heroes, period.
To give an example, she's used those forcefields to knock out the Hulk.
It's further implied that if Sue didn't adhere to the rule of heroes not killing their enemies she could easily defeat most of her opponents by simply generating force field bubbles in their bodies and/or vital organs and making said force fields expand.
In Enemy Of The State, Wolverine admits she's the only one of the four that scares him. Sue actually demonstrates how dirty she can fight if she wants to, by turning his retinas invisible, thus blinding him, then wrapping force fields around his lungs and threatening to crush them. That Wolvie was under HYDRA's mind-control at the time didn't stop her from subverting the I Know You Are In There Somewhere Fight to hell and back, and she even lampshades this with something along the lines of: "I don't care who's controlling you, you come into my home, threaten my children, did you think I'd go easy on you?"
Whoa Bundy: Used in the origin story, when the team and members are named.
Worthy Opponents: Ben Grimm and Incredible Hulk to each other. Banner himself has said that if Hulk ever really cut loose, Ben would probably be the only hero on Earth with even a chance of slowing "ol' Jade-Jaws" down.