First of all I NEVER EVER clean the TV when it has been on. Let it set and cool. Then I spray a microfiber cloth with Pledge Multi Surface (I use the purple twisty cap I think its lavender) then I whipe the screen clean.
I use the Pledge Multi Surface to clean just about everything except my fish tank, windows, and mirrors in my house! It is AMAZING. However it HAS to be the multi surface stuff or it will leave "implossible to remove" smudges on the screen.