Too me the best is the A1200. AGA and accellerator madness. I like the PCMCIA slot that I can use for NIC, Compact Flash and SCSI expansion. Having a tiny sized harddisk storing a crazy 4GB of data I think is pretty cool. Also the formfactor, at least it does not remind me of a standard PC :-).
But the prize for cuteness goes to the A600. Just too bad it cannot be expanded (accellerators are too hard to come by) and ECS is somewhat limited IMHO.
I'm just not into big box amiga's.