I got Braid, Defense Grid TA, Foreign Legion: BoB, and Crash Time II all for $10. I played about an hour of Crash Time, and I have to say that it's totally worth $4. The physics aren't incredible (it's a little old) but everything is destructible, the cars handle well, it's pretty, and there are some really interesting concepts. I played a few minutes of the Foreign Legion game and wasn't very impressed. It was hard and there wasn't much depth to it. I've played Braid and DG before, they're both pretty good games. DG does get quite hard after the first 5 levels or so though.
Kind of tempted to pick up GTA4, I have the disc version (not currently installed), but I think I'm kind of done with that game. I'll also pass on Stalker, it doesn't appeal to me whatsoever (hard, scary, ugly, dirty, buggy, and primarily a RPG).