5. Star Trek IV: The Voyage Home (1986)
Alright, we now arrive at the weirdest Star Trek movie ever... The Voyage Home. It picks up where The Search For Spock ended, with the Enterprise crew heading home in a stolen Klingon Bird-of-Prey, fully aware that upon arriving they will be put on trial for their crimes (busting McCoy out of prison, hijacking and destroying the Enterprise, and trespassing on a forbidden planet). On arrival however, they find Earth in a bad situation. A mysterious probe is orbiting the planet and causing catastrophic storms all over the planet. The reason for the probe's visit? It's trying to find humpback whales, which are now extinct on Earth. In order to save the planet, the crew must use the Bird-of-Prey to travel back in time, find two humpback whales, and bring them back to the future.
The Good: This film flows better than most other Star Trek movies, and also features more humor. Additionally, it gives a good amount of screen time to almost all of the cast, where the former movies were usually "Kirk and Spock save the day".
The Bad: Seriously, humpback whales? I've seen this movie at least five times and that still baffles me.
The Ugly: Spock mind-melding with a whale. In a swimsuit. With a whale.