|Hate to see you go, love to watch you leave!|
Why, a drow anti-paladin, of COURSE!
Heh. I kid, I kid.
A couple guys I knew when I was a teen playing 2E had some gonzo characters, but a particular fave (of at least one of the guys) was a drow anti-paladin. The guy was also fond of jumping up from his chair during combat encounters and showing his character's exact movements for every attack.
ANYway, a favorite character I haven't played? Again, I mostly GM, so my limited time as a player has, therefore, limited the number of characters I've played in my time. Also, I've depicted so many NPCs in my time that there isn't a character I haven't stepped into.
But, if I had to choose, it would have to be some sort of assassin-type character that wasn't just a skulker in the dark. He would be equally proficient in appearing in plain sight as a smooth talker, casing potential targets face-to-face as well as from the shadows.