Most favorite all around would be the Amiga 1000. From before its rollout, I was in love with that machine and bought one when they became more affordable by '87, around the time A500/A2000 were released.
In practice though and what I use currently the most today would be the A3000. Couldn't afford an A3000 when they were released ($3200+!) and by the time they were affordable ($500+), the A1200 was already out and went with that machine instead because of its promising AGA architecture and came bundled with OS3.0.
Today I do not own an AGA capable machine and I'm fine with that. I like the looks and feel of the 3000 too much to go back to one. It's just a more practical machine for me w/ more sensible expansion options. A1200's case and styling though is nice, don't get me wrong. Great little computer for sure.
Least favorite would be the A500 (too big as already mentioned) and A4000. Even though A4000's tend to be problematic, it's not a terribly big deal changing out caps. I just don't care for the case and styling of the machine. It was overpriced too from the get go, which didn't help my perception of it at the time. At least when the 3000 was released, that was considered a state of the art, hi-end mainframe machine and was priced competitively with similar computers at the time. Built in FF/SD and you have the makes for one sexy Amiga computing experience. If you're gonna have a computer sitting out on display, may as well make sure she's worth looking at
