My favorite was an A3000/060/PIV I owned for several years. I broke it up and sold it in a fit of stupidity (I wanted a computer that would work with my WinCE PDA).
My second favorite would be the A1000 bought used in 1990. Still runs perfectly!
After realizing what I had done with the A3000, I bought a slightly dodgy (bad sound) A4000 on ebay. I've added a Prometheus card for networking and Voodoo graphics. Wish I could afford accelerator and PIV cards, but I can't swing the prices they bring on ebay :^(