Who are some of your favorite non-recurring Star Trek characters (2 episodes or less per series)?
Annorax from the Voyager episode "Year of Hell" really sticks in my mind. A tragic character doing incredible amounts of damage repeatedly to save one person. This episode is probably my favorite from the series.
Don't know if he's my absolute favourite, but I love Timicin from TNG's S04E22 "Half a Life". He's a good, dedicated and kind man who would have been a great long-term partner for Lwaxana Troy, but for the fact that he is about to commit ritual suicide as he's about to turn 60 as a part of a culturally enforced practice called The Resolution.
Played by David Ogden Stiers, he has great chemistry with Majel Barrett, and their relationship is a believable one. He's a man torn between challenging his society for the chance to keep living in order to save it (he's the lead scientist trying to stabilise their sun) while finding love with Lwaxana, and not rocking the boat and simply doing what's expected of him.
Hmm, I just discovered Iggy Pop's music for the first time so I'll go with Yelgrun, the Vorta in The Magnificent Ferengi, DS9, Season 6, one of my personal favorite episodes.
If you've never listened to The Idiot or Lust For Life then drop everything you're doing and put them on, they are fantastic albums.
I also liked Mark Twain (I know) when I first saw TNG because as a young Canadian I had no idea who he was. It made me read a bit more about the person and his work.
Apparently it's common to forget about him, since since the crew of the Enterprise did the same for a few years, until he had to remind them of his existence.