There are two ways to unlock the Hulk in Marvel: Ultimate Alliance 2 for the Xbox 360 and PS3.
For you non cheat enthusiasts out there, you’ll need to collect five Gamma Regulators.
While you are in the game playing, enter this code:
- Down
- Left
- Left
- Up
- Right
- Up
- Down
- Left
- Start
Character cheats are the only ones that will allow you to save after use, so this should unlock Hulk permanently.