Cooler Master Stacker @ Viper Lair
 

Though it's not that important yet, the ability to go from ATX (and the various flavours) to BTX is something that separates the CM Stacker from the rest of the field. At $165 USD, this case isn't cheap, but if you're keeping an eye out for the future, this is a case that will "switch teams" for you if the need arises.

http://www.viperlair.com/reviews/cas.../cases/stct01/