In terms of peer it is between Sakura and Shikamaru....I'd day Hinata is more than a peer.
In generalization, I'd say Iruka....he was the first person to vocally accept Naruto (since miss Hinata was shy).
Closest circle is Sakura- sister, Kakashi- teacher, Hinata- lady of interest, Shikamaru- best friend, Iruka- brother, Lee- competitive rival/ close friend, and Jiraiya- psuedo father/ grandfather.
He technically also considers Sasuke as his best friend with Shikamaru who is probably his actual one in deeds.