Fujitsu offers the Celsius Ultra. The PC is said to be the fastest air cooled gaming system that has been released up to now.
CPU Intel Core i7 Extreme 975
Graphics card 2x EVGA Geforce GTX 295 Ultra Clocked
Motherboard FTS D2778-X1, Chipset: Intel X58
Memory 6 x Samsung 2,048 DDR3-1333