Processor
We're recommending the same Athlon 64 X2 5600+ as in our Grand Experiment alternatives. AMD has faster dual-core chips available—such as the Athlon 64 X2 6000+—but our price/performance comparison article revealed it to have a poor value proposition. If you must go with an AMD chip for this system, the 5600+ is your best bet.

Motherboard
The Abit KN9 SLI was a fine choice for our Grand Experiment alternatives, and it's an equally good choice for our Sweet Spot alternatives. It has two PCI Express x16 graphics slots with SLI support, dual Gigabit Ethernet controllers, six Serial ATA ports, and a host of overclocking and monitoring/tweaking options courtesy of Abit's μGuru tools.

Graphics card
It's no secret that AMD's first effort in the DirectX 10 world has fallen short of expectations. Nonetheless, the Radeon HD 2900 XT is a decent alternative to the GeForce 8800 GTS 640MB. The Radeon offers roughly equivalent performance, and we're fond of its CFAA tent-filtered antialiasing modes. Of course, the 2900 XT does cost more than the 8800 GTS, and it also has higher power consumption and noise levels.

Storage
We have two storage suggestions in our alternatives list. The first is Seagate's Barracuda 7200.10 500GB, which is our recommendation for users who care more about a long warranty than higher performance, lower noise levels, and a lower price tag.

The second is Western Digital's 150GB Raptor. We don't expect you to trade either of our recommended 500GB drives for a speedier drive that only has 150GB of capacity, but we do think the Raptor can be a good complement to either the SE16 or the 7200.10. Thanks to its 10,000-RPM spindle speed, the Raptor provides the best performance with random I/O seek loads of any Serial ATA drive out today, making it an ideal operating system and application drive. The extra performance could come in handy for storage-intensive applications like video editing, too. With both 500GB and 150GB drives in one machine, you'll enjoy the best of both worlds: high speed where needed with high capacity riding shotgun.