Unlock All Comics And Movies:
On the review menu screen, quickly enter the following on the D-Pad:

Unlock All Comics: RIGHT, LEFT, LEFT, RIGHT, UP, UP, RIGHT, START
Unlock All Movies: LEFT, RIGHT, RIGHT, LEFT, DOWN, DOWN, LEFT, START

Unlockable: Iron Man:
You must get four homing beacons per act. Each time you do you get a piece of Iron Man's armor. By Act 5, once you've located all the beacons, go save Iron Man.

Unlockable: Professor X:
Complete all of the Danger Room missions.

Unlockable: Deadpool:
Finish the game.

Hint: Infinite Tech-Bits:
There are two instances where infinite tech-bits are available, the boss rooms where Lady Deathstrike and Archangel are. Opt to portal out and then come back, all crates and barrels will respawn in either area. If you want to waste enough time, you can get all the bonus skill points that are in the 100K range for every character you desire.

Hint: Unlimited Experience:
There is a room in the Act 4: Holding Pens where enemies keep spawning. From the exit of Sewers West, go straight until you get to a T intersection. Go right until you hit another dead-end and proceed right a second time.

The first room on the right will have two pods where enemies spawn and a tracker nearby. This tracker activates the spawning. Trip it and enemies will begin spawning without limit.

Hint: Party Skill Bonuses:
Attack Doubled ... Party uses Age of Apocalypse costumes.
Plus 5 percent XP earned ... Party consists of Nightcrawler, Sunfire, Toad, Deadpool -or- Juggernaut, Magneto, Scarlet Witch, Toad.
Recoup 20 energy per kill ... Party consists of Juggernaut, Colossus, Wolvernine, Rogue -or- Cyclops, Jean Grey, Gambit, Rogue.
5 percent of damage is added to party health ... Party consists of rogue, Deadpool, Gambit, Wovlerine -or- Storm, Scarlet Witch, Rogue, Jean Grey.
Damage increased 5 percent ... Party consists of Gambit, Bishop, Cyclops, Iron Man -or- Bishop, Deadpool, Nightcrawler, Gambit.
Health regeneration at 5 per instance ... Party consists of Magneto, Professor X, Scarlet Witch, Juggernaut.
All resistances increased by 10 ... Party consists of Storm, Iceman, Sunfire, Magneto.
All statistics increased by 10 ... Party consists of Colossus, Juggernaut, Iron Man, Magneto.
Party health increased by 15 percent ... Party consists of Iron Man, Scarlet Witch, Wolverine, Bishop -or- Nightclawler, Storm, Colossus, Sunfire.
Energy limits increased by 15 percent ... Party consists of Cyclops, Jean Grey, Iceman, Magneto, Toad, Professor X.
More techbit drops ... Party consists of Iceman, Professor X, Iron Man, Deadpool.