I'd just want an old CPU built on a new process. Tell me to my face that none of you would want a 486 or Pentium that could clock in the 3-4 GHz range.
And speaking of a new process, I'd like a 76 core Pentium III. The Coppermine P3s took up around 21 million transistors, as compared to my 32nm FX 8350 @ 1.6 bn transistors. Ooh, and how about a Pentium Q: A quad core, hyperthreaded Pentium 4, just to see how high Netburst could do with new tech (my guess is 5-6 GHz)
Meh, since I'm unconstrained by reality: mayhaps a slotket for Athlons is in order. That'd be pretty cool. On a more practical note, I would also quite like an ISA USB card that could also act as a mass storage driver for legacy BIOSes (being able to dd a Windows 98 image into a flash drive would be very convenient).
Dual Katmai Pentium III (450 and 600MHz), 512ish MB RAM, 40 GB HDD, ATI Rage 128 | K6-2 400MHz / Pentium MMX 166, 80MB RAM, ~2GB Quantum Bigfoot, Awful integrated S3 graphics.