to compare the Apple dispay to the Dell is crazy. Yes, they basically look the same and use the same LCD panel, but the Apple is a SWOP certified System and ICS certified, the Dell is not. It's not just the panel you are looking at, it's the backlight and the electronics behind it. Apple makes a better monitor, that happens to look better than most other monitors out there.
I will also second Eizo, LaCie, and Iiyama. Sony used to make some good CRTs, but i'm not impressed with their LCDs. To me, Eizo make the best color, but Apples are great too. If you are going for color, don't buy a dell. If you are going for size and features and price, the buy the dell.
my 2¢
-JE