The popularity of 3D in movies has got people talking more about 120hz on TVs. This has been driving me crazy that people are putting so much importance on this without realizing what a sham it is.
So a quick rundown of what I'm talking about. Hertz (hz) on a TV is used to measure how many times the screen refreshes the picture in a second. For as long as we've had TVs they've been running at 60hz. This number is used because it matches the current coming from the wall and was easy to use that to keep the timing in sync. All the movies, tv shows, etc you've ever seen is either 24hz or 30hz just for reference.
So the selling point with 120hz and higher TVs is that they provide a smoother picture because the the screen refreshes more often. The problem is that the content you're watching is still only 24/30hz, so what it's doing is upconverting. I think a really good analogy is 1080p, another thing people will tell you about when you go buy a new TV. When you get your 1080p TV, the sales guy is going to tell you that you can watch your old DVDs which are 480p and get an upconverting DVD player to make them 1080p, or you can get a Blu-ray player and watch movies in native 1080p. There is no 120hz content that you can go out and buy now, nor is there any plans for it. Your computer is capable of outputing 120hz, but usually only at lower resolutions like 480p. Now we run into the even bigger lie. All these 120hz TVs won't accept a signal higher than 60hz. So even if you did have content that was 120hz, your TV would be downscaling it to 60hz, and then upscaling it back to 120hz.