My personal best uptime for my Mac OS X system is
11:44AM up 12 days, 22:51, 1 user, load averages: 0.62, 0.58, 0.42
That's almost 13 days with a TiPB G4, 256M ram 10G HD. This is honestly the best uptime I've ever had for a personal PC, Windows or Mac. I've been crashing Mail, iCab...