Dell has a 30" monitor with the same resolution but the response time is slow at 15ms. Actually, that 2560 by 1600 Dell has more horizontal pixels than the iMac—"27-inch models: 2560 by 1440 pixels "—but the iMac is true 16:9 widescreen movie format rather than the distorted 16:10 of most large screen monitors. Also, the Apple monitor is E-ISP technology, 178º viewing angle with little to no distortion of color or brightness and it's instant-on to full brightness LED backlit instead of CCFL. The Dell monitor on your link seems to have a 8ms response time. nice.
What's the response time of the iMac's monitor?
Looks like 5ms... that's the speed of the E-IPS tech.
That Samsung 25" with keyboard and mouse is a hell of a deal... it's 5ms as well but still CCFL.
rather than the distorted 16:10 of most large screen monitors.It's not "distorted" per se. It's actually a perfect aspect ratio for watching 16:9 content in a way that lets the user interface overlay controls not always have to be fading in on top of the actual movie (I hate it when they do that all the time!).
Then when you are not watching video content, you get a desktop that is actually the same aspect as the Golden Ratio, the most aesthetically pleasing rectangular shape.
I know that sounds weird, but the Ancient Greeks figured out a lot about that ratio and in particular why some rectangular shapes just seemed to "feel better" than others:
http://en.wikipedia.org/wiki/Golden_ratio
Personally, I think the LCD makers have begun to make 16:9 screens in order to save a few bucks, not because it makes more sense.