Opium: yes we do!
Top seven ugliest (shouldn't it be most ugly?) species in Star Trek:
7. The Ferengi
6. Klingons
5. Those fish looking things in the episode where Lwaxana is in heat.
4. The Insectoids
3. The Alien Nazi (the one in Zero Hour, had to be specific)
2. The alien Nazi (the one in the Killing Game, the Hirogen)
and the number one most ugly species in Star Trek:
the Reptillian Xindi