[quote name='Zantetsuken']I have two Marvel Vs. Capcom 2, one for Xbox and the other for PS2. I want to sell one of them, which one should i sell and which one should i keep?[/QUOTE]
I think the XBox version will net you more money, and they're more or less identical ports, so you might as well sell the XBox version in my opinion. It also depends on which system's controller you prefer for fighting games, though.
EDIT: Looks like the PS2 version might not be up to par after all. My bust!