I like Iruka the best, because unlike everybody else, he looks at people for who they really are, rather than who everybody else decides they are. He was orphaned by the Kyuubi, but instead of scapegoating Naruto like everybody else, he got to know Naruto before he decided whether Naruto was responsible or not. Unfortunately, as the series progresses, he seems to fade into the obscurity of a minor character (at least to the point where I am). You didn't put him in the poll, so I voted for my second favorite.
My second favorite character is Sasuke (pre-curse XP). He is mostly calm and collected, and doesn't let his emotions get the better of him (for the most part). He also knows what he wants, and knows how he will get what he wants.
My third favorite is Orochimaru, simply because he's a snake. (Orochi, when pronounced another way, is Hebi, snake. XD)