Of course Brick, but he has played at both positions. I don't remember where was a thread in wich was linked an article about this topic that said he was more effective when played at SG.
I think that, if he has shown to be solid at PG, it's because the kid is a genious: the same reason that explains why Wade is very OK at PG. But I think his natural position is SG. If he can be more effective playing at PG so the other team suffers when pairing deffenses it's another question. But as far as I've seen runing the team, he's not a PG. He is a combo guard, like Wade, like Roy...
Does it really matter? Of course not, as long as Kings win. But maybe it worth start him at SG so he start developing abilities without the ball instead of waiting him to improve his abilities as PG.