Hmm, my favorite characters... would have to be Sesshoumaru, Rin, and Sango.
Sesshoumaru is just such a complex character. And I was pulled to be intrigued by him because he wasn't on any side but his own. And I just love his transformation through the series from uncaring and cruel to more caring and kind. The wonders an 8 year old (age ?) girl can do to someone's heart. Heh.
Rin is just too cute and is one of those kids who can be really annoying but you love them anyway. She's just so kind and selfless and very brave for a girl her age. How many children do you know who wouldn't run away from a man who just snarled at you with red glowing eyes?
Sango is one of the few older manga girls I like. I usually don't really like the girls introduced in manga but Sango is really cool. She's a skilled fighter but is also very caring.
My least favorite... Naraku and Kouga.
I'm usually a fan of the main bad guys but Naraku just didn't really catch my attention too much except for the fact that he caused pretty much every single problem in the series but I just wasn't too impressed with him.
Kouga is one of those characters that I both like him and hate him. But I hate him more than I like him. He's just too... possessive. I don't like how he kept pursuing Kagome when there was no hint that she liked him at all. It was cute at first but after a bit he pretty much came into the category of freaky stalker guy.