Devil May Cry easily. Not all the sequels of drastically varying quality, but the Hideki Kamiya original. Good god I loved that game. I beat that game once a day, every day for, like, three years. o.O Name any ridiculous thing you can possibly do in that game, and I could usually do it. I've never replayed a game so many times before or since. So obviously, it's one of my favourite games ever. I don't touch it anymore though, for obvious reasons. :P