For the most decades since the television has been invented it has been changed so greatly no one could ever imagine in the begining: we have LCD television, LED television, plasma television and OLED television, we have from edge-tit to full array televisions, from 120 Hz to 600 Hz, from 2D to 3D televisions.
For many many years people needed tv sets for only one purpose: to get what the mass-media was broadcasting. You already know all about that: news, shows, movies and so on. For now… the first thing you must consider when buying a television is its purpose. What are you going to do with it? Are you only watching the news and movies and all kind of entertaiment shows? Or are you going to use it for doing something else? Something like using it as a computer monitor or playing Nintendo WII or any other type of game consoles? Or do you want to browse the Internet using your TV?