My all-time favorite character is Spock. I like him the best because he is neither at home on Vulcan or Earth. His home is the ENTERPRISE. His logic and intelligence are an important part of his Vulcan half but his flawed feeling human side is just as important.
My favorite has been and always will be Spock. Through Star Trek: TOS, Star Trek movies, and Star Trek books, Spock has always been the most--ranged--character. I have no idea how to say it, his character is just the one that was the most well crafted, versatile, new, diverse.....etc.
So, top 3 spots:
3. Mark Lenard/Q