Of the four presented, the halfling whore is the only one that hasn't had any playtime. She's still just a concept.
My shaman is a lot of fun, I'm playing him now. (Keldas' player is DMing for us while dinkeldog is away.)
Goat-boy has the advantage of being stuck in RttToEE, which is a fine adventure in which to set the story.
The old lizardman is a character I've had a long time, you can see bits and pieces of him in the game I run (Wulf's Lazy Days). I'd say Wulf borrows the most from him...
Wulf