20-22" isnt really full hd gaming, the res is 1680x1050 1080p is 1920x1080. if your sys can handle it get 24" with 1920x1200
but if you insist take your pick http://www.newegg.com/Product/Prod [...] name=22%22 get one with 8000:1 contrast ratio or higher lower than 5ms response time, also read the reviews.