OK... so I've had:
1) PowerMac 6500/225 - no problems at all.
2) PowerMac B/W G3 - no problems at all.
3) PowerMac Dual G4 Gigabit - Logic board died.

4) iMac G4 800 - no problems at all.
5) Mac Mini Core Solo - no problems at all (except when
I broke the internal audio cable)
6) 17" iMac C2D - no problems at all.
7) PowerBook G4 - no problems at all.
8) 13" MacBook Pro - no problems at all.
My wife has a 2008 white Macbook - only issue there is the cracking case (which will be replaced).
Guess I've had pretty good luck, too, esp. since 6 of those 9 machines were bought used (only the Mini, my wife's, and my MBP were new).