Some of my fave 4.5" head sculpts:
Relics Scotty
Unification Spock
Sarek
Sela
O'Brien
Lwaxana
Guinan
Trelane
Tuvok
Khaaaaan
Saavik
Season 6 Troi
Cadet Beverly
1940's Picard
Q
Quark
Borg Queen
Sisko
DS9 Worf
Lore
The Doctor
Chakotay
Neelix
I had forgot about a lot of them, I have them all standing in front of me! The Dixon Hill sculpt was a big improvement on the old Picard one, along with DS9 Worf and Troi. And the Doc is fantastic, I'm actually reading his (Robert Picardo) short book, the Hologram's Handbook.
I have got Gloria from Cleveland, but not regular or Generations Guinan yet.
Also the Trails and Tribble-ations Dax is a very good likeness, and Bashir looks good as well (just waiting for him to arrive in the post).