I consider myself to be a part-time Trek fan so that's maybe why this list doesn't even make much sense to me. YMMV.

From best to worst:
1. Star Trek II: The Wrath of Khan
2. Star Trek: First Contact
3. Star Trek VI: The Undiscovered Country
4. Star Trek IV: The Voyage Home
5. Star Trek III: The Search For Spock
6. Star Trek (2009)
7. Galaxy Quest
8. Star Trek Generations
9. Star Trek: The Motion Picture
10. Star Trek Nemesis
11. Star Trek Insurrection
12. Star Trek V: The Final Frontier
13. Star Trek Into Darkness

ETA: Because artiofab doesn't read good, he didn't notice that this list was also on the main page. He hangs his head in shame and will assume the party escort submission position.