I think this is fun. I might like to pick up a 386sx/33 (my first PC...had an Apple II clone for years, but my real interest in computers started with the 386), a Pentium 166 and Pentium II 350. I think I have my old Athlon XP laying around somewhere, though I'd have to dig around quite a bit to find it. I know I still have my Athlon 64 (still in my old case) and my Core 2 Duo is still sitting in its motherboard in my closet. So, I could pick up three chips and have all of the processors I regularly used.
I used to have a 486 DX/2 66 Overdrive chip, which I pulled all the CPU pins off of and soldered a steel ring to, and I used it as my keychain for about 5 years.