I have this one and a lot of people say it's the best. It is expensive at 100$, though.

http://www.monstercable.com/productdisplay.asp?pin=4115

Of course, it's on the PS2. Kind of an old game like maybe2-3 years ago not too sure

OK in this game you were a guy who possessed some kind of monster that you could control and he would kick everyone's ass. After acquiring a certain amount of experience you could make your monster ''evolve'' into a stronger form and all I remember is the last form of the monster was called Thanatos. Does anyone remember this game? I'm sitting here thinking about nothing and everything and I couldn't remember the title of this game.