These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: X-Men Legends
Crowning Moment of Funny - After unlocking him in the sequel, Deadpool is full of this, such as proclaiming "And now, I'm better at whatever it is Wolverine does!" after levelling up; but the Crowning Moment comes if you have Deadpool in your team when you face him as a boss - the two Deadpools start arguing about who's the real Deadpool.
Jean Grey in the first game, thanks to her Telekinetic Combat passive. Combined with Psionic Strike and Psychic Shout, her sheer power comes close to Prof X's. The fact that many of the endgame enemies are Sentinels and robots, who are resistant to psionic attacks helps mitigate this.
Storm in the first game is even better than in the second. She has powerful attacks and Leadership, can weld, fly, her whirlwinds stun foes and her lightning can hit enemies in the other room and even link. She's just a very useful character.
Magneto in the second game. Developed judiciously, he can clear entire rooms in seconds, has excellent crowd control and is pretty much unkillable, while sending the entire team's XP through the roof and solving every puzzle on his own.
Any kind of gear that has +X Damage on it (not any specific damage type) amplifies any damage dealt by the character, making them powerhouses. Jean Grey had a similar passive ability in the first game which amplified any psychic damage she did, making her the strongest character after Prof X if levelled properly.
After proper leveling, Nightcrawler's dash attack makes taking out entire rooms full of mooks hilariously easy.
Ho Yay: Pretty much every cutscene has a moment or two of Xavier and Magneto, Team Mom and Team Dad, keeping the bickering siblings that are the two teams from coming to blows. "Charles and I discuss everything before a mission," he once says to Toad, who says that Magneto should be in sole command, very much like one parent telling the kids that decisions are made as a unit.
That One Boss: In the second game, Sugar Man can kill a character in one hit, and there's no way to tell this attack apart from his regular ones, which hit like a truck. What's worse is that Sugar Man has a nasty case of Gang Up on the Human and will follow the character the player controls all over the room, ignoring the rest of the party unless they get between him and your character. AI teammates never seem to get hit with the OHKO attack either. The battle boils down to controlling a character with a ranged attack, firing a couple shots at him, then running away once he catches up to repeat the process (made easier if you have Magneto, Storm or Jean, who all have strong ranged attacks and can fly).
Mr. Sinister, with an attack that causes everyone to run away from him, is more annoying than dangerous (but he's dangerous too, with a little red beam that will take you out.)
That One Level: In the first game, the team has to evacuate a crippled naval vessel before it sinks, while Jean Grey tries to hold it together telekinetically. An escort mission with a strict time limit and one of your most powerful characters sidelined? Yay! And then Wolverine accidentally stumbles into ankle-deep water and instantly drowns and you have to reset…