The LG SL8000 series have the best input lag for playing games. You can get the 42 inch model for under a grand, has won numerous awards including,
EISA - best product "best value LCD TV" 2009 - 2010
All the new Sony and Samsung models suffer from lag input, the Samsung LED's are even worse.
Im in the same boat as you, I would of considered the SL8000, but 42 is to big for me and 37 to small.
LG 42SL8000 Televisions TV/Audio/Video