Ok so recently my P4 Northwood 3.06Ghz beast has been having some issues. Namely the spark gap that seems to have formed in the power supply.
I could just go out and replace the PSU for $30 or so but I think it's probably time to get a new computer anyway.

Basically I want to get some recommendations. E.g. CPU brand / model, DDR 2 or 3, graphics card, etc. I also need to know how powerful a PSU I need to get cause I haven't bought a new computer since the days that 400W was enough.

I really want a fairly good price/performance ratio because my disposable income is not huge.

Also I will put it together myself as paying an extra few hundred for a brand name computer is ridiculous.

So yeah, suggestions?