All of my views on the characters have changed, because they've all grown as characters throughout the series.
Mat most of all, as he started out as the semi-dependable, mischievous kid who was always able to wriggle out of a situation, only to turn around and get into another one. As we watch him interact in steadily more serious situations, we come to realize that Mat isn't a bad guy at all, really just Chaotic Good. He pushes through the hard times with the dagger, his own force of will keeping him alive, then he goes on to help Rand in the Waste, showing that he really is a dependable friend, and ends up dying for it. As we see him continue to grow with more "I'm not a bloody noble!" lines popping up in the text, we see that he's still stubborn and resisting the inevitable, but when the time comes and he finally see that he can help Rand and the World by accepting his fate as Prince of Ravens, he takes it on graciously.
Perrin holds the converse honor for me. He's been the most consistent character in the books, while Mat has been growing up and shifting radically and Rand has gone on to go insane, Perrin stayed stalwart and calm-headed. Until he met Faile, he never changed much, really just staying as the voice of gentle reason, a little introverted, but always a strong leader and a strong spirit. He came back to the Two Rivers and learned that he couldn't just depend on himself all the time, and that his friends weren't always going to be there to help him back, so he took in Faile. The big change comes from his stubbornness converting itself into aggression in a wonderfully lupine way.
Elayne, Min, and Aviendha all pretty much start to gravitate toward each other as far personality shifts go, which is dramatic from their starting personas, but comes about so smoothly that you hardly notice in until you actually stop to think about it.
Egwene goes through some pretty interesting transitions, from trying to be an adult to trying to be worthy of the Amyrlin Seat, her ambitions change dramatically and yet her odd mix of stubbornness, kind empathy, and honor all stay fairly persistent, though ow she acts in accordance to them changes as she realizes new truths about the world. I think it's fairly funny, that one scene where her and Elayne are talking and Elayne says "I'm going to be Queen of Andor" and Egwene relies that she is going to be the greatest Aes Sedai ever, or something to that effect.
Moraine starts being an overpowering force of personality, almost to a point that she starts to oppress everyone else's, and really seems to be a bit of a b*tch, to say it pointedly. As it progresses, especially after she meets her sisters in the borderlands, then later in the Stone, she goes through a few personality shifts as she learns that she has to trust in her companions a bit more. It amazes me still that she finally realizes that she has to give ground with Rand in order to gain any, and she goes through with it. I cannot wait for them to rescue her from the Tower of Ghenji, and see what changes she's gone since she 'died'.
Lastly Lan and Nynaeve, the've both managed to soften each other up, and somehow they've managed to umbue each other with a deeper sense of duty and strength. Their dynamic is amazing, how they're constantly dodging and weaving from each other in a metaphorical fashion, and then they finally come together right in the middle of Nynaeve v. Moghedian.
That's all, I guess...