Destructoid has a great question for the gaming masses. It is not "What are the best games?". Rather, it is "What are the games you can't live without?"
I cannot live without:
The creepy, creepy original! I've played this game, including all side quests, somewhere around 20 to 30 times. If I'm bored, and want to play a game, Shadow Hearts goes in the PS2 and I don't look back. Sometimes I'll only play the first half of the game. Sometimes I'll go back months later and play the rest. It doesn't matter. Shadow Hearts is my fall back for any video game down time.
Shadow of the Colossus
I haven't played this game into oblivion, but you really can't. You have to wait for it and let the need to play sneak up on you. If I didn't have this game, even when not interested in playing, I would cry. How much do I love SotC? I have a coat, necklace, and rubber stamp with the weak spot sigil on them. That's right: a rubber stamp. My mail goes out in Colossus Style.
Any of them. Seriously. Occasionally I get this urge to kill vampires and zombies with nothing but a leather skirt and a whip with a vampire's soul in it. Or maybe just the Coat of Pimping (+2) and the Claimh Solais. Anyway, when I get into a Dracula killing mood, any console becomes my friend and the DS lets me have my Castlevania anywhere, including conferences for work. ;)
What games can you not live without?