Voted 68000, since I only have an unexpanded Amiga 500 atm. About what's Amiga and not...sure there are computers that do capture some of the Amiga feeling, but to call it Amiga it has to be an Amiga. Otherwise it's just a computer with some Amiga feel.
I would call a Natami still a Natami, although I'd love to buy one asap.

...and yea, a CUSA Amiga is still an Amiga, despite it doesn't run Amiga OS natively. Call it crippled?