Shouldn't really matter too much. Anything that supports DVI should work fine. Personally I'd see if you can find something LED backlit. Better quality and lower power use, so win-win there. Otherwise, just go to some big box electronics retail store like Best Buy, Fry's, Microcenter, etc, and see what they have on display. Pick whichever appears to look the best to you within your price range.
Was given a Power MAC G5 2.3 dual core and was wondering if anyone had any suggestions on a good monitor for it for $100-$300. I've only used imacs before and never had to buy a monitor.