Oh, I've got several of these. XD
Once, I REALLY didn't like Meroko, from FMWS. I mean, around the middle of the series somewhere, I just really started to dislike her because of the things she was doing. But by the end of the series, she had become my second favorite character. XD I think she's fantastic, now! XD
There was also a point where I really hated Takani Megumi, from Rurouni Kenshin. She just grinded on my nerves from the very beginning! XD However, once the series reached the close of the Kyoto Arc, I didn't mind her so much anymore, and I'd even venture to say that I started to like her as a character.
I really didn't like Haruko from Air very much when I first started watching the series. But, once again, later on, I really liked her as a character, and thought she played a very human and very moving role in the end.
A character that I once went back and forth in liking and disliking is Hino Rei/Sailor Mars, from Sailor Moon. XD At first, I thought she was really cool, but particularly annoying at times. But by the end of the first season, she was my very favorite Sailor Moon character.
Another character (what is this, number five? XD) would be Wolfwood, of Trigun. I wasn't exactly sure just what to think of him at first, but by the end of the series, I decided that I did like him as a character.
The sixth character I'll mention is Madoka Wakamatsu, from FMWS. At first, she was annoying and snobby, but after a while, she didn't bother me as much, and I began to like her as a character.
The last character that I'll mention is Izumi, also from FMWS. I didn't much like Izu-kun when he first showed up, but now he's my third favorite character in that series (just behind Takuto and Meroko
).
So there you have it. Dynamic characters are just plain interesting. XD Granted, there are a lot of dynamic characters that I didn't mention, simply because I liked them from start to finish, and since this is the thread for "Characters You Changed Your Mind About," I'll leave it at that for now. XD