Roger wants an HDTV that he can use for gaming, and he needs it to have low latency. Leo says that the key feature is response time. Old style TV sets had a response time of virtually zero, which is why they're still the best option. LCDs are about 4 milleseconds, which isn't bad, but it does give some motion blur. Latency has to do with connectivity. If he can turn off processing, he'll get better performance.
The chatroom suggests going over to DisplayLag.com to learn more about specific TVs and what they're display lag is. They also have a great article called The Best HDTVs for Gaming. The best overall is the 2013 Sony KDL-55W900A.