I use the $25 monster stuff. I've had one bottle for about 2 years now. I picked it up for like $10 or so when i worked at Ccity. Its in a blue spray bottle and came with a cloth. The stuff lasts forever as long as no one is putting thier hands all over your TV. I have a LCD projection hitachi with a matte finish screen.
And no... windex is not the best choice
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
. make sure whatever you use is made for electronics.