The big debate is whether to get a 720p or 1080p. According to CNet I'd probably just be better off with a 720p LCD since its not larger than 50".
I would say go with the 1080p right off the bat. 720p will serve you well enough with any kind of broadcast signals. Simply because most broadcasts don't have the bandwidth to give you a true 1080p signal, and the network HD broadcasts max out around 720 p...even sports. But if you have a BluRay player or a gaming console like the PS3 or X-Box 360, you'll get a far superior image on a 1080p set.
As for the 120 MHz refresh rate? I can't say that I'm a fan of it when it comes to watching movies. Because that refresh rate is in contrast to the quaint 24fps look of film. It makes movies look more like they were shot on video, and they lose some of that "cinematic" quality.