People's "old" computers.
Recently I've picked up four old computers, only two of which were legitimately slow.
First:
Poweredge R510 with Dual Xeon X5672s (3.2 GHz Quads w/HT) and 64 gigs ram for $10. Seriously, what the hell, one stick of ram is worth more than $10.
Second\Third:
Two Dell Precision T3500s with Xeon W3503s (2.4 GHz Dual-Cores), one had 2 gigs ram, the other 4 and both Quadro NVS 295s. Got both for $5. They are DDR3 and Socket 1366 though so one's already at an i7 940 and 12 gigs ram, the other's going to get some quad-core Xeon (or maybe the i7 if I can find a 6-core) and 6 gigs ram. Thing is, the upgrades are dirt cheap as I have the ram on hand and the quad-core 1366 Xeons are like $20. The 6-cores $80-$150.
Fourth and most recent:
HP Z200 with a Xeon X3440 (2.53 GHz Quad w/HT), 8 GB RAM, 500 GB HDD, Quadro FX580 for free. For whatever reason they put XP 32-bit on it (without PAE) but hey, it's a free quad-core with 8 gigs ram that's faster than any $300 tower you'll go out and buy today.
Really though, with the exception of the T3500s what is it with people acting like some of this stuff is ancient?