in terms of the films, for me its (in order of how much i like them):
1. The Wrath of Kahn
2. The Voyage Home
3. First Contact
4. The Undiscoverd Country
5. The Search For Spock
6. Nemesis
7. Insurection
8. Generations
9. The Final Frontier
10. The Motion Picture
as for the series its:
1. The Next Generation (just has the edge for me as i grew up watching it)
2. The Original Series
3. Voyager
4. Deep Space Nine
5. Enterprise (other than season 3 (which had some okish episodes), it was awful)