Apple - iMac G5. I have an old Pentium Xeon desktop at work (a cast off from a failed EIR project) and an old iMac (another castoff), but I've been thining that getting a real iMac might make sense.
Asked my buddy Rob over at Apple, and he recommended the iMac G5. It is a 2GHz PowerPC with a 20" LCD screen plus it has the newest Tiger on it. Compared to the home brew thing. Here is the pricing
$1800 gets you a 20 inch screen, 2GHz PowerPC, 512MB DDR400 memory, 250GB hard drive, 8x DVD DL drive, ATI 9600 128MB ram.