I'm a big fan of the G3 Clamshell iBooks. I've still got my first one, I've overclocked it from 300mhz to 400mhz, and I think I'll attempt to put 10.4 on it today with XPostFacto.
I've got a couple other Macs (G4 eMacs, and a 1.25ghz G4 MDD PowerMac,) they're nice and quick but not nearly as fun as the Clamshell.
