KG without question. No contest. He absolutely embodies Celtic Pride and he is almost singularly responsible for the culture that has been embedded in this team since 2007. That's why I'm glad he's going to retire a Celtic... I want him to be a part of this organization in some capacity long after he retires.
There's a lot to like about Pierce and Rondo as well, of course... but KG would absolutely be the favorite. Just like KG is most certainly Doc's favorite. He's everything to this team.