I've been happy overall with the Dell Ultrasharp U2xxx[H]M. Several sizes to choose from, 90 degree rotating stand, and perfectly fine for office work and casual gaming as well. I like the ones with a 16:10 aspect ratio, but to paraphrase Brian Cooley, it's easier to bring Israel and Palestine together than to broker the religious wars over monitor aspect ratios 
When researching monitors I look at the reviews on tftcentral, as they're mind bogglingly thorough. They will also tell you what LCD panel each monitor uses, e.g. an HP and a Dell monitor could both use the same panel from LG. That means the image quality should be close, and the major differences will be in the ergonomics, menu system, etc.