liver,

the motherboard is the most important decision. It controls all other purchase decisions.

Of course you have no say so when you buy a Dell, but that's why they're so cheap.

mitz

Yeah, do your homework on the MoBo. AMD or Intel CPU doesn't really matter (although some people will violently disagree with me :p ). Sweetspot these days is probably 2.6 - 2.8 GHz (very powerful but not overpriced). 512MB DDR RAM as a minimum, decent graphics card (Matrox G450 seems to be used a lot), two good size, quiet (!) hard disks (Seagate or Western Digital), preferrably with 8MB buffer and definitely 7200rpm. A DVD+RW drive to load software and to archive data is also a good idea. If you want quiet components(besides the hard disks) pick a good power supply for the case (e.g. Enermax) and a quiet CPU fan (such as Zalman). It's more expensive first but really pays off in the end.
And, of course, a really good sound card makes all the difference! I recommend RME. Can't go wrong with it.

Hope this helps,

MisterBlue.

I would second MisterBlues comments except for the Enermax power supply. While Enermax seems to make a decent power supply they are not quiet. I just tore mine apart this weekend and did some mods to it. I replaced both fans with Panaflos and knocked the voltage on the internal one down to 5 volts to make it run much quieter. Don't recommend this unless your experienced however since the caps can retain lethal voltages even with the power supply unplugged.

Since Motherboards were brought up earlier...

Which Motherboards have the best reputation as a DAW?

For both Intel and AMD because I'm not picky either.

I don't have any personal experience there ,as I am Mac based, but I would recommend Intel chipset mobo's for P4/P3 machines, and I've heard good things about the NVidia chipsets for Athlons. Avoid Via chipsets like the plague.

Another consideration is the features that are crammed into today's mobos. A number of them are not needed for the DAW, and you may find better performance with a mobo that doesn't have built-in video audio, LAN, kitchen sink....

I like Asus mobo's for P4 and Athlon personally, though, as I said I don't have any experience building PC DAWs. But just about every PC I have built started with an Asus mobo.

Check this out, its a great resource for mobo reviews, comparisons, etc., but nothing specifically audio-related: http://www.motherboards.org

mitz