I'm looking for 2-4 cores with virtualization. I prefer AMD, although I know that Intel is doing better on the high end nowadays.
It's important to have really fast memory speed as well.
I want to start playing around with virtualization. Not that I have a real need for it, just that I'd like to be able to run older versions of windows and such on my linux OS while Linux is still running. This is so I can do testing with IE6, IE7, and IE8.
I tend to use a lot of memory. That's because I'll run a lot of stuff at the same time. Having stuff swap in and out is a major pain.
AMD / Intel
I've always liked AMD. For one, they support Open source drivers in their ATI stuff. Besides, I've never had a bad experience with them. Their chips seem, to be, subjectively, better than Intel's. AMD's low end hardware is much cheaper and much better than Intel's low end stuff.
64 v. 32?
I don't really care, although I prefer 32 bit architectures. I don't see the big reason for 64 bits except memory addressing.
I want a good, solid motherboard. It has to allow very fast memory. If it has dual DVI on board, it would be nice. Otherwise, I'm going to not use the video card so it doesn't matter.
I want to make sure that the networking on the motherboard supports Linux well. I don't want to use a closed-source driver if I can avoid it.
Ditto with the sound chipset.
It has to support the fast speeds of the CPU and the amount of memory I'd like.
Plenty of SATA. At least four.
Video Card: $52
The video card has to support dual DVI. I like ATI since there is an open-source driver in the linux community. I refuse to use closed-source drivers if I can avoid it.
The card must absolutely positively be well-supported by the open source ATI drivers.
On-board memory isn't too important. Neither is the 3D capabilities. I'll take what I can get, but I doubt I'll use it.
I really, really like dual monitors. Dual DVI is a must. VGA just doesn't cut it on monitors.
4 GB, very fast. This should be about $90.
Hard Drives: $90
I want 2 drives of the same size. I don't backup very often, so I'd like to run a RAID array.
In terms of storage, I really don't use a lot. 100 GB is more than enough. 250 GB is overkill.
So 500GB total storage on 2 250GB hard drives.
250GB are about $45 a drive. This comes to $90 for 500GB.