Spock, with Data as a close second.
I hate Data. And he was far worse after his emotions got partially activated (although I was pleased when he gave Yar a good pounding).
When they were dreaming up the next generation, they asked "How do we replace Spock?"
They used at least 4 characters: a second-in-command, a science officer, "the logical one", and a mind-reader, and still couldn't pull it off.
I consider the campy quirky side of Spock when he would succumb to his primitive emotions, fall in love, cry, or connect with hippies to be his greatest virtue.