If I were you, get the 360. Yes, yes I am a 360 "fanboy" but 99 dollars for that deal? That's a steal IMO.
Well, TBH, it depends on what you like to play. 360 has the shooter games, the better online service, the better "arcade" games you can buy, and the better exclusives... but thats just me. Like I said, I'm a "fanboy".
PS3 has The Show, Socom, and a blu-ray built in.