I can only refer to the games that are also on xbox 360.
As mentioned Bioshock 1 & 2 were great if you like horror survival games, Fallout 3 & New Vegas are just friggin great epic RPG/shooter crossovers (mainly RPG) & Borderlands is all kinds of fun. The best game across platforms has got to be Red Dead Redemption though.
For something a little different and family appropriate, Ghostbusters is pretty great too. I bet you could probably get it pretty cheap.
No retail Wii, DS, or 3DS releases this week. Those threads will come Thursday when they announce the digital downloads for the week. The Wii Rock Band 3 DLC is the same Def Leppard tracks as listed below. Gold Member Deals of the Week (Tuesday)