My most finished game is Resident Evil 4, finished it about 100 times combined, on the gamecube and PS2 but that was done during summer, averaged about 6 hours for a full playthrough.
Games I install, remove, don't play for a few months/a year, reinstall play, remove are very rare, and now I no longer have any backwards compatibility(my PS3 can't play Ps2 games and my 360 nearly dies when trying to play anything that isn't 360, might look for a wii just to play my gamecube games), there are four games, all from around 2000 that I still play. Clive Barker's Undying, American McGee's Alice, Final Fantasy 9(emulator using original discs) and Alien Versus Predator 2(would play the first, but I never finished a single mission in that game and I doubt it even runs on this PC)