Dosu - We've been over this time and time again, but to sum it up: he's extremely interesting and well developed for a supposed "supporting/minor" character. He's got a pretty hax jutsu at chunin level that still works with the powerscaling of Naruto, and he's one of the smartest characters in the series. I still think one of the reasons Kishimoto killed him in such an OOC moment was because he was too strong and he didn't know how to get rid of him.

Kotetsu and Izumo - AKA "those two guys in naruto". The most unbreakable tag team duo I've ever seen. They aren't too impressive combat-wise, but they work really well in tandem and I think that's interesting.

Aoba - My buddy Scarbucks convinced me of this one. His crow abilities were freakin' awesome.

Ajisai/Animal Path - Cute girl who can summon huge animals to protecc or destroy things? Yes please.

Kidomaru - This spider guy was smart, cunning, and tactical. He only had one fight, but it was hella impressive.