My favourite would be..
Kakashi, 'cause he's really strong and really nice. Don't know, from the first ep. i saw him, i'm just completely in love with him <3 ;p
Sasuke was my fav. character for a long time, but when i got to the point where he nearly killed Naruto i just started to despise him... Still, Sasuke is one of The hottest anime/manga guys EVER ;D
For some reason i really like Temari. Don't exactly know why, 'cause she isn't in the anime or manga really often, i just think of her like the ideal of a woman : tough, strong, smart and sarcastic. Really love that ;p
My opinion of Rock Lee would be the same as Sakura's ;D at first he was just a creepy stalker-san, but in the Chuunin exams i completely changed my mind ;p
In the end, the one i LOVE the most would be Naruto. He's just amazing. Kishimoto did such fantastic job portraying this character, it's so full of life it's amazing ;D when you think about the things he had to suffer, you can just be amazed to how determined this guy is and how much he's accomplished :]
The ones i hate the most would be..
Kabuto for one. I hate the guy. Hes just the one who's getting on my nerves the most. Not just being a rat for Orochimaru, but the whole portraying of this character is just... simply annoying ;D
Ino is also extremely despised by me. I just think she's completely useless as a character. She's always shown as a coward and the weakest link for team 10. Also the selfishness is bugging me alot.
Deidara. Reminds me alot of Ino, so that would be the main reason ;D but i think he is just too full of himself. His whole introduction to the readers was too big. The fight to take cute little Gaara. From the beggining - a bad guy ;p Nothing better for the narrowed-eyed guy ;DD