Part 1: Sasuke > Kakashi > Itachi > Orochimaru > Hiruzen > Asuma > Kimmimaro > Jiraiya > Gaara > Lee
Part 2: Madara > Sasuke > Itachi > Kakashi > Tobirama > Minato > Gai > Deidara > Sasori > Orochimaru
Liked Sasuke a lot since part 1 because he is a badass (He is based on Killua Zoldycks character). Kakashi was awesome in part 1. Itachi was a badass when he was first introduced, taking down all the Jonins with relative ease like a boss. Orochimaru was the greatest villain at the time. Hiruzen was a great character. I always liked Asumas design, one of the few characters that smokes. Kimmimaro was awesome, Jiraiya had great personality, I liked Gaara when he was psycho. Lee had the greatest character development besides the MC's of course.
In part 2 a lot of the part 1 characters had gone down the gutter either because a new awesome character was introduced or the part 1 character simply lost everything they had going for him. Madara was my favourite since chapter 560, Sasuke still retains second place, Itachi got bumped over Kakashi because we found out a lot more about him. Kakashi is still in 4th, I like his dog theme a lot. Tobirama got placed in 5th since we actually got some depth to his character, Minato got placed in 6th since we actually got some depth to his character. Gai is in 7th because he is badass when in gates, I like his flashback, I did want him to die in a blaze of glory though, Naruto giving him chakra pissed me off and reminded me why I hate the character so much. Deidara got placed pretty high since his introduction, but went to the bottom because others showed up, same thing goes for Sasori. Orochimaru went down only recently, he was still 5th until he became Sasukes lapdog, which throws his original likeable personality down the toilet, I really do hope he has enough decensy to leave and go backs o his evil deeds by the end, as a conclusion to his character, instead of ending the series off by following Sasuke.