Great read. Here's my personal history just for fun.
AMD K6 233Mhz, Pentium II 400Mhz, Pentium III 550Mhz Katmai, Pentium III 700Mhz Coppermine, AMD Athlon 1600+, Pentium 4 1.8a (Northwood with 512k cache), Pentium 4 2.4Ghz Northwood with 533Mhz FSB, Pentium 4 3.2Ghz EE, Pentium D 920, Core 2 Duo E6600, Core 2 Quad Q6600, Core 2 Quad Q9550, and Core i7 920.
I've also owned a mobile Intel Celeron, mobile AMD Sempron, and currently have an Intel Pentium M 1.7Ghz from past and present laptop purchases.
The last 4-5 desktop upgrades have been more frequent since that was about the time I was done with college, and now I have a full-time income to feed my gaming habit. I still don't waste money buying the absolute top of the line, but my overclocked "2nd or 3rd best" CPUs keep me in line with the latest and greatest available for about 1/3 of the cost.
My favorite chips were the Pentium III 700@933Mhz with no voltage changes, my Pentium D 920 running at 4.0Ghz, the E6600@3.0Ghz (stock was a huge performance advantage even over my 4.0Ghz Pentium D 920 though), and the Core i7 920 I'm running at EE speeds of 3.2Ghz with ease (1.225V on the CPU and 1.6V on the RAM at 8-8-8-20 timings). Although the Core i7 is a fire breather compared to the Q9550 it replaced, the extra cooling required is worth it to me for the "needz more faster" aspect of it.
