I love my iMac, I hate my iMac.
I've owned my iMac for about 2 years. I use it for music and photos, mostly, and when it's not in use it makes a great picture frame for displaying my photos.
BUT
My LCD screen suddenly started devloping vertical lines just like these.
So, while I love my iMac - don't buy one unless you get the extended AppleCare warranty!
Here's an online petition to get Apple to correct this problem. (yeah right)