The worst two classic Trek films were the first one (The Motion Sickness) and the Wrath of Khan. Khan himself must be one of the most annoying characters in screen science fiction. Give me Jar Jar any day over that. Easily as bad as Hayden's Anakin.

Undiscovered Country was by far the best film with the original crew. Final Frontier is ok. In some ways at least it's better than the two films that immediately preceded it. But I think Undiscovered Country is the only genuinely good original crew film.

Generations is to an extent an original crew film. In some ways it's good and in some ways it's a major letdown. I'm not thrilled about any of the Next Generation films, but they're all watchable. I agree with C3PX that the Borg Queen was a dumb idea. She was also a bloody annoying character.