The contrast ratio isn't as important as the bit depth per color. To help speed up response times, manufacturers like to use 6 bit per channel processors. These monitors, as I have painfully found out, can not reproduce subtle gradations without banding and dithering. This is the primary reason I went back to my 19" CRT, I can't stand the banding. Unfortunately, manufacturers do not list the bit depth when they spec out the monitors, except when it is an actual selling point for them, as is the case with LaCie's and Eizo's high end units. It's not uncommon for these units to have 10, or even 12 bit panels. The panels themselves can not reproduce more than 8 bit, but they can process larger color spaces, allowing more accurate convertions from 32 bit color to the screen's 24. For us, that's overkill.

Loren makes a very good point about the Dells. Same panels as the Apple Cinema Display (at least when comparing 20 inch models), but with slightly inferior backlighting and case design, making for more uneven illumination across the panel. Having used one though, you don't see a difference unless the units are side by side and you're looking for flaws. Dells are half the price and have the added benefit of a slew of input options that the Apple lacks.