I think it probably depends what you get. I've got a 19" widescreen TFT monitor (
Acer AL1916W) - great for watching DVDs and general working, and it runs software such as Flight Sim 2004 absolutely fine. I think it's great, and of course then there's the obvious advantage of desk space as well. They do cost quite a bit more than their CRT counterparts though - it depends how much you want to spend. For a basic 17" CRT you're looking at £65 or thereabouts; my 19" widescreen TFT was £179 by comparison.