Do you like multiplayer games? 360.

Do you like single player games? PS3.

There's other stuff that factors into it, but those are pretty huge ones. PS3 has some of the most goddamn amazing single player experiences available, and the 360 makes multiplayer such a seamless, social event that it really can't be beat.

If you're in the middle of the road on that, well... yeah, start writing up a list of console exclusives and go off of that. MGS4 was the deal breaker for me, really. I'm not much of a Halo guy.