While resolution, contrast, and brightness are important specification, it's best to check out in person. See how clear the text is. Recently I went to shop for LCD with friend. My impression is the clarity varies quite a bit with similar spec. And it's not neccessary the more expensive one has clearest text. Some Sony and Nec LCDs just look ok, not worth the price. My friend ended up buying an 17" Envision LCD for $180(after rebate) at CompUSA. It's not well known brand so it's inexpensive. But the text is very sharp in native mode(1280 x 1024) and it offers 3-year warranty, while many companies only offer 1 year warranty.
You can also check online review, which I find very helpful.