Here's my setup: Mac mini and a Dell 2005FPW 20.1" display
http://homepage.mac.com/chris.platts/files/setup.jpg
... also shows my iPod photo, KVM switch, LaCie BigDisk 500GB drive and a Belkin 4-port firewire hub.
I have my Mini running into the DVI input, my PC connected to the VGA input, and my digital satellite PVR (a Sky+ in the UK) connected to the S-Video input. The photo shows the Dell in Picture-in-Picture mode, with my Mini's desktop and the Sky+ s-video feed in the upper left.
It's an absolutely beautiful display! The panel is the identical component to the Apple 20" cinema display. Whilst I'm obviously fine with paying anything extra for the excellent Apple computers, I can't say the same about the displays. Although Macs may contain 'commodity' parts (the RAM, drives, etc), the Apple price tag's worth it because of all the other Apple-only technology (integration, OS X, design, etc). However, with a display, it's the commodity component itself (the panel) which is what you'll be staring at for hours on end. Apple can really only bring 'neat design' to the party. When you factor in the Dell's VGA, S-Video, Composite, picture-in-picture, picture-by-picture and audio support, as well as the ability to rotate 90-degrees to portrait mode....
Well, let's just say I wasn't about to shell out extra for an Apple display whose only benefit over the Dell is a cuter bezel and better cable management! With the Dell's lower price and metric buttload more features, I'm willing to forgive it its crappy Dell logo and plain exterior!
[edit:] just read Kaltek's link. I read the same article before I got my display. It does mention a good point that you might need to consider if you're looking to get a 2005FPW 2nd hand. Early revisions had backlight bleed problems. No new unit should be one of those revisions. Mine, bought in November, is an A03 revision (or maybe A04, I forget...) and is absolutely fine.
One final note: in portrait mode, this thing's a monster (I can put up another pic if you wish!). However, for some inexplicable reason, the Mini's Radeon 9200 seems to slow considerably when the screen's rotated. This isn't a problem with my PC (a Radeon 9800 Pro). I'm not sure if the cause is hardware, driver, or OS X-related. My gut instinct would be that there should be no extra demand on the hardware in portrait mode, since the display is the same resolution and colour depth, just with the axes reversed. Having said that, it's still fine for viewing portrait images and for reading long pages of text. Not much fun when flinging windows around the screen though!