I 2nd Castle Crashers Its soo fun LOL! And I can't even think of anything else since I only have a PS3 now and no Xbox (But I know Castle Crashers is on XBLA)
I've got 10 hours clocked on mine, and i've gotten to the final world, i think.
haven't gotten all the bandages, but i've cleared all the dark world levels up to hell, still need to snag two hidden characters (not counting bandage-unlocks)
edit: yes, it will last you a while if you don't mind ramming your head into the same 5 second level for a while.
i'm taking a break right now, the 10 hours were accumulated in about three days. addicting.