My list has been well covered, but here are my picks:
R5-A7 (sometimes known as G8-R3, or whatever it is, from the Royal Starship)
R5-X2 (Jabba's Ep 1 droid)
Queen Padmé Amidala (Return to Naboo / purple)
Tey How (Neimoidian Controller)
Skull Head Spacer (Rum Sleg)
PK Droids
Aldar Beedo (Pod Racer)
Clegg Holdfast (Pod Racer)
Pilot Battle Droid (the ones with the blue stripe) w/ decent articulation
Captain Of The Republic Ship @ Start Of Movie (Maoi Makador?)