I just bought a 55" Sony 4k

http://www.amazon.com/Sony-XBR55X850...ywords=4k+sony

By far worth the money. 60 FPS/Hz at 4k. I dont play many FPS, but MMO wise its been amazing. CNET had it rated as the best 4k large screen out there for gaming.

Frankly I am thinking of getting the 49" as its almost too big.