Well over a year ago, I built this computer:
80GB 7200RPM Maxtor (IIRC) HDD
AMD Athlon XP 2600+
MSI 52x32x52 CD-RW drive
LG DVD drive
A-Open nForce4 motherboard with onboard GeForce 4 MX, firewire, USB, sound
A nice small case with 350W PSU
256MB RAM (IIRC PC2600, but I'm not sure)
It's a nice PC, and it cost me 300 euro. The keyboard, mouse, monitor and speakers I already had. I got the motherboard and the CPU second hand, something that couldn't be done so easily with Macs.
If I went for a Mac, I'd be paying twice as much for a Mac mini. EDIT: no, I wouldn't. They didn't exist.
No thanks.