Killzone 3 - didn't like KZ2, so I'm not really interested in KZ3.
Infamous 2 - found the demo for the first game boring, so yeah, not interested.
LBP2 - Rented LBP and sent it back the next day. Found it boring and creating levels was too time-consuming.
SOCOM 4 - Still not sure about this one.
Gran Turismo 5 - not a fan of racers
Versus XIII - need some gameplay videos & more details before getting excited.
So out of those games, it's between Versus XIII & Socom 4.