The COOLER MASTER Stacker 830 is a monster of a computer case. It has nine external 5.25" drive bays, four internal 3.5" drive bays and seven expansion slots. It's very big and made almost completely of aluminum, so it has plenty of air circulation to keep your components cold. It also has plenty of room for high end components such as water cooling or the new NVIDIA 8800 line of graphics cards.
The original revision of this case had a problem that made the installation of graphics cards extremely hard, but COOLER MASTER has fixed this and I can't find a reason not to recommend this case now. It does take up a lot of room though, so make sure that you have space for it before you purchase it.