My Pentium 4-HT 3.0Ghz burned out, so I switched to an older AMD chip. I was using XP until I took a gamble and installed WIndows 7 a few months ago. Worked good for a few days, but then the processor began feeling the hit so eventually I moved to Mint(An AMD64 3800+ with an nVidia 6800 Ultra PCI-E card, lol). I've toyed with linux ever since early high school but never had the time to fully get to know it. The 4-cd slackware install back in 2003(?) was memorable, though.
I guess I've finally settled down with Mint x86 for my main PC. I wasn't able to install the x64 version because it didn't like my NEC DVD/RW, but I've only got 2GB of ram so it's not a big deal.