So far, I've not gotten a chance to collect a lot of these....
but, from the ones I managed to collect, my favorites are:
Mon Calamari Trooper
I'm sure there's some better ones, but I haven't gotten my hands on any of the Amidala variants, Plo Koon, or Saesee Tiin.........
I still also want K-3P0, Imperial Officer, and Ellors Madak (I want two of them, so I can customize one into Lott Dodd (The Duros and the Neimoidians look remarkably similar)