1 : My main rig (see my sig) - obviously my main PC is the fastest flashiest PC I can afford at the time on my measly slave wage.
2 : Pentium 1 200 vanilla with a Matrox 2D card and a Voodoo 1. Running Dos and windows 95. Aureal sound card. Would change clocks from 75-200 as required.
3 : K6-3 550 with a TNT2 Ultra and Voodoo 2 SLI. Soundblaster Live or AWE64. Running windows 98se. The ultimate Glide machine.
4 : Athlon 64 4000+, with 1950 xtx SLI and an audigy. Lanparty mobo. Mint case. Totally silent with overkill cooling. OC'ed to high heaven. The ultimate XP single core rig. Just to have a pimping looking PC, inside and out.
I actually own all of these. I could deal with just having them. I have no plans to build another - having given up on tualatin because finding a good working mobo is like winning the lottery.
I5-2500K @ 4.0Ghz + R9 290 + 8GB DDR3 1333 :: I3-540 @ 4.2 GHZ + 6870 4GB DDR3 2000 :: E6300 @ 2.7 GHZ + 1950XTX 2GB DDR2 800 :: A64 3700 + 1950PRO AGP 2GB DDR400 :: K63+ @ 550MHZ + V2 SLI 256 PC133:: P200 + MYSTIQUE / 3Dfx 128 PC66