Behold: The gayest moment in Star Trek.
Huh...um...well, I guess the closest thing to a gay character was Dax from Deep Space 9. Dax wasn't really gay, so much as occasionally bi-curious. She once made eyes at Vanessa Williams and that was pretty gay. Oh, and there was an episode where she kissed a woman to whom she was married in a previous incarnation (Trills are a little like Time Lords). Yup, Dax was like the gayest thing to happen to Star Trek, and then she married Worf. So much for that.
That's it really. Yeah, Crusher dated that guy who became a woman ('nother Trill, and then she dumped him/her) and Riker hooked up with an alien from a planet with no sexes but he'll bang anyone (see?). In 45 years there hasn't been an actual gay character on Star Trek. I guess that somehow on a show about space commies who have sex with aliens, androids and holograms, it would have been going too far to show two dudes having a drink together in Ten Forward. I'm a big nerd and I love me some Trek, but they kind of dropped the ball on this. To make up for it, here's a picture from George Takei's wedding:
Maybe we'll see some diversity on Star Trek: The Next, Next Generation.