Use a really soft dry cloth, like a paintball safety glasses cloth or something similar. Just use that. Or you can also use pledge dry clean on a smooth cloth.
Buying A TV.
This all depends on type, size, and budget. For a complete TV buying guide, see the following guide:
http://electronics.howstuffworks.com/tv-buying-guide.htm
A large television screen will use more power than a small one although the difference isn't great. A television uses power to process the incoming signals and prepare them to be sent to the display...