I think it depends on the type of game. Visit the Input Lag Wars thread and ask them. Im only passingly familar with this issue. The gamers there can help you.
I think the Philips 5507 has been mentioned as tops for big set input lag, but be advised it uses a Red Chinese Chi Lin panel. Not top panels from LG, Samsung/Sony, and Sharp....so Picture Quality may suffer. However it should be passable, if gaming is a priority.
Epson 8350 / Panasonic AX-200u / Optoma Graywolf 92" / Draper Luma 92"
Samsung 51F8500 / Panasonic P50ST60 / Vizio P502ui-B1 / Sony 50W700B LCD
Sony S790 / Panasonic BDT-220 / Roku 2 XS & Roku 2
Samsung F550 / Speakercraft CS3 / Yamaha YAS-105