We've had quite a few ViewSonic LCD monitors fail in our company. The good ones look good, but the quality control seems to be lacking. Planar is also an inferior maker, as are a lot of the Asian off-brands - high failure rates and inadequate specs, but those sub-$200 price tags are apparently too enticing.
I'd recommend NEC, Samsung, or Sony. They cost more - and there's a good reason. $500-$700 isn't much for a top quality LCD because you'll be able to use it for years. The Apple Cinema Displays are the best on the market, as Swordmaker's post reveals, but they cost even more.