Take a pick:
A 1997 P1 200Mhz, 48MB RAM (upgraded from 24MB), and some other stuff (HP Pavilion something or another, don't remember much) running Win95
to
A 2001 P3 866Mhz, 128MB RAM, 16MB ATI Rage Pro (one of the white-tower Dells) running WinME, with me dropping in 2000 eventually.
OR
An early-mid 90s Power Macintosh 6200 running OS7 (not sure, since I'm at college right now and due to memory) with unknown specs
to
The above-mentioned P1
I don't know which one to pick, since I can't exactly remember old performance that well (mainly an issue with the Mac going to the P1). I do remember catching Carmen Sandiego on that old Mac and making ink-wasting picture printouts in whatever passed for Paint on the old Macs - ahh, childhood.