Antec Skeleton
I love it. It looks like a cool custom modded case, without all the effort of cutting up and modding a case myself. I need to take some decent pictures of the finished rig.
The skeleton isn't a good idea for anybody with children or pets in the house, since everything is exposed. Also not the case to take to LAN parties, for the same reason. If you're a disgusting slob who routinely spills things near computers, this isn't your case. For all the rest of us, this case is great.
Before I put my rig together I was a little worried about dust buildup in this thing, since it's so open. Turns out not to be an issue at all; the skeleton moves so much air that barely any dust has a chance to settle. What little dust does collect in the corners is very easy to clean out, since there aren't any walls in the way.
For air cooling, it doesn't get any better. And the fan makes a good nightlight too, so I don't stub my toes on furniture in the dark.