The only Linux Distro that I have thats stayed on a PC, is actually on the kids old 233 LapTop, and thats Mandrake 6.1 and its running better now than it ever has!!!
I have never bothered to up it because it does what is asked of it, its a basic Internet machine that has wireless access to my router, its got StarOffice 5.1 on it and access to the Printer again, obviously over the wireless, and its well... Nice.
Every other Distro I have had on a PC never realyl lasts too long, but that LapTop was a farily good spec when I installed it... Its done well.
I did have a Linux only main PC but due to the increasing lack of faith in Linux, I have been moving away from it... Not to windows, because thats even worse, but rather away from the PC completely and back to my Ataris.