7. Sybok - Star Trek V: The Final Frontier
The Final Frontier is a bad, and boring film. There is too much unnecessary dialogue in a film whose aspirations don't match the budget. Sybock, Spock's brother, was the only high point. Played wonderfully by Laurence Luckinbill, Sybock was charismatic, and charming and was able to become a religious cult leader of sorts. A unique idea in the Star Trek lexicon that hasn't been explored. At least at that point and time. Still, despite his performance, the script he was given was lacking.
6. Kruge - Star Trek III: The Search For Spock
When it comes to Kruge, it's really just a lack of material that held him back from being higher. He was threatening, and commanding, he had a presence and he was played by Christopher Lloyd. He's even the reason why James Kirk's son, David was killed. It all sounds like a surefire winner. Yet, Lloyd wasn't given the chance to chew the scenery like we knew he could. Had he had more air time, a heftier script, or maybe just more to do, maybe we'd talk about him as an all-time great.
5. Khan - Star Trek: Into Darkness
The reason this Khan isn't beloved is because no other version of Khan will be embraced by the fandom. It's the gatekeeper mentality. This Khan, played wonderfully by Benedict Cumberbatch, was a snarling, imposing, quotable, dynamic villain who did just about everything he sought to do. It was different than the original Khan, sure, but it was great in its own way. I argue that if he was a new character to the franchise, no one would have an issue with how the character was portrayed and would be celebrated as such. Because of his name though, he gets unfairly dunked on. This Khan is great and I still quote his scenes all these years later.