Ed is absolutely correct (And yeah.. it's fun now that I don't have to do it all day for a living anymore... LOL!)
By the time you buy a decent quality sine wave inverter.. you might as well have spent the few extra bucks on a 12v tv in the first place. I have several small inverters for wot nots.. lamps, battery
chargers etc.. stuff that isn't picky, and 1 true sine wave one.. at a measly 100w, for my computer and one of my old TVs, which was really sensitive (And small!) It cost over 120 bones. (And that was cheap in comparison to others)
However, the advantage is that the inverter is available for other stuff besides the TV.
I do however, stick to my rule.. if it can be had in 12v to start with, I run direct whenever possible. It's just cleaner and more efficient.