I'm buying a new TV soon and I don't know whether I should buy a plasma or lcd. This tv will mostly be used for gaming (through xbox 360) and maybe occasionally watching movies and some other stuff streaming from my pc. The size will be around 42". Any information would be awesome.
You should just go to Best Buy/Sears/Frys and look at tv's. Don't be bothered by the salesmen throwing technical jargon. Each tv will look slightly different. Get the one that looks best to your eyes. DLP FTW
IMO a good plasma set still is best for HD movies, like Avatar on blu-ray. However LCDs, esp. with LED backlighting & 120Hz refresh rates, come pretty close and also use less power and are lighter if you're considering a wall mount. I have a couple Sony LCDs and a Pioneer Plasma - when it came to watching Lost in HD or Avatar, I would watch the Pioneer even though I just have a futon sofa in that room, no recliner slouch - er, couch like in the rooms with the Sonys .
120Hz HDTVs and 120Hz PC monitors operates differently. All HDTVs only accept 60Hz video inputs. 120Hz monitors accepts dual linked DVI-D (60Hz each).
120Hz HDTVs does internal video processing to insert frames to make movies play smoother and give the "live" like look. This causes input lag for gaming so you always want to switch to 60Hz mode.
120Hz PC monitors are refreshed by both DVI-D inputs so simplistically speaking, they can different parts of the screen are "refresh" between the two inputs. that makes for smoother gaming experience. This does nothing for movies to the best of my knowledge.
^^ Correct above. Almost all 120Hz TV's use interpolation to get the difference between two different frames, which is unacceptable for gaming. There are also conflicts with blue-rays (24Hz native) for this very reason...