I own an NEC PA271W. I love the insane menu options and the fine-tuning that the monitor allows.
Prior to the purchase, I was also looking into the Apple 27" and the Dell U2711, but in the end I eliminated the Apple because of the glossy screen and limited connectivity options, and then eliminated the Dell due to issues with QA and lack of deep pro controls.
The PA271W was pretty much the king at the time that I bought it. However, if you really want to go uber, Eizo's newest model in their ColorEdge professional line is the CG275W, their 27" competitor. This is allegedly the new king, however Eizo prices are really high, and unless your computer display is closely tied with your career, it probably isn't worth it.