My Aluminium PowerBook G4 is brand new.
My Wallstreet Powerbook G3 had the black paint scraped off it a little on the corners, and the battery-module release arm wasn't very snug anymore...
My old PowerBook 120 or 240 or something (I forget the specs) had the battery short out, so we just ran it on a power supply.
As for "portable", if you count the old Performa and the multitudes of Mac Classics, then they're all covered with the multicolour Apple stickers, and the SCSI ports have pins snapped and bent (but they still work - most of the time). The iMac DV is perfect.
I don't dish out an awful lot of abuse - my PowerBook is my baby.
Don't touch my baby, or I keel you.