1) Tandy TRS-80 Color Computer Mark III (I think it was a 1024 KHz Motorola 6809E CPU). She didn't overclock, but did have 512 KB of RAM
2) Intel 286-4 MHz. Wow, 4.117 MHz after soldering on a new Turbo.PLL chip.
3) Intel 386SX-16. I could downclock it with a flick of the Turbo switch
4) Intel 386DX-33. Never did overclock it.
5) Intel 486DX-2 50. Pushed that FSB to 33 MHz on an old 486-GVT motherboard (2 x 33 = 66 MHz).
6) AMD K5 133 PR75. Poor thing performed abysmally, considering it was still a 486 at heart. I returned it.
7) Intel P166 MMX. Pushed FSB to 75 MHz (2.5 x 75 = 188).
8) Intel P233 MMX. Pushed FSB to 75 MHz (3.5 x 75 = 263)
9) AMD K6 266 MMX. Pushed FSB to 75 MHz (4 x 75 = 300).
10) AMD K6-2 400. Never O/C'd it, as the motherboard was a VIA MVP-3 based and couldn't OC worth a damn.
11) AMD K6-3 400. To replace the poor K6-2 that burnt up. Ever since then, I've religiously checked my CPU fans. Never overclocked.
12) Intel P3-500 Katmai. Pushed to 560 MHz (112 * 5) on the venerable 440BX.
13) Intel P3-550E Coppermine. Pushed to 733 (133 x 5.5). Still running 24/7 stable today for the last 3 years on a no-name 440BX board (MyComp TI6NBD+).
14) AMD Athlon K7 500 Slot A. Pushed to 560 MHz (112 * 5). Burnt up due to inadequate cooling (damned things were like a fireplace).
15) AMD Athlon K7 650 Slot A. Pushed to 728 MHz (112 * 6.5). CPU failed after I tried to utilize a home-made Gold Fingers Device on it.
16) AMD Athlon K75 800 Slot A. Pushed to 896 MHz (112 * 8). CPU and motherboard (Asus K7M) up in smoke after lightning strike took out system.
17) AMD Athlon Thunderbird 750 Slot A. VIA GFD, I've got it running 24/7 right now at 1000 MHz (100 * 10) in an EPoX 7KXA+ KX133 system.
18) Pentium 4 2266B Northwood. Running 2992 MHz (176 * 17) in an Asus P4T533-C (i850E) after performing a Turbo.PLL mod to get around the 150 FSB limitation of the 850E RDRAM chipset. Running SETI.
19) Pentium 4 2400C Northwood. Was running at 2880 MHz (240 * 12) as the CPU wouldn't not go any further.
20) AMD Athlon XP Barton 2500+. Running at 2200 MHz (200 x 11) in an A7N8X DLX 24/7 stable with SETI installed.
21) Pentium 4 2600C Northwood. Currently running at 3705 MHz (285 x 13) 24/7 and dedicated to the OC.com SETI project.
It's quite a list, and I've been burned by some stupid mistakes in the past (IE CPU fans).
//Edit: In my "not-being used CPU" pile, I've got:
6x Athlon K7 600 MHz Slot A's (all DOA)
1x Athlon K75 800 MHz Slot A
1x K6-3 400
1x P2-233
2x P2-400's
2x P2 Xeon 400 MHz 512 KB L2
1x P3-500 Katmai
Countless numbers of 486's (ranging from 25 MHz to 100 MHz)
