I still love the characters I loved before
My taste didn't change so much, that I didn't swoon over The Young Wolf Robb Stark or over season 4 Jon Snow, or over Jaime Lannister in general. I am still rooting for Sansa Stark and enjoying Tyrion's wisdom and wit. I am still interested in Theon's story and still have a weird attraction for Ramsey.
I still hate the characters I hated before
The great thing about re-watching a show, is that this time I can skip over all the story lines I don't care about, namely pretty much the entire story of Danaerys Targaryen. I don't know what it is about her (it might just be the actress) but I just can't stand watching her without being annoyed. I also think that her story so far was quite repetetive. Unfortunately from season 5 on, she has scenes together with Tyrion as well as later with Theon and Yara Greyjoy, so I missed some of their scenes, too, and man, I missed Tyrion.
Other story lines I skipped (though I don't nessecarily dislike the characters) are Bran in season 4 and Arya's entire Bravos story line which is nerve recking.
Some characters I hate a little less now
Near the top of my hate list was also Melisandre. I'm still no big fan of her (I mean, come on, the things she does are really messed up) but I can appreciate her a bit more now. In the end, she is an extremely powerful witch. She definitely killed Renley, and she might have caused Robb's and Joffrey's deaths, too. Also, she is able to bring someone back from the dead which is incredible. I don't like Melissandre, but I do think that you shouldn't mess with her.
Some characters I appreciate a lot more now
The second time I watched Game of Thrones I found that I enjoyed so much the smart characters, who are not as remarkable as the main acts but are actually pulling the strings in the background. There is Tywin Lannister who, despite his evilness, actually knew what he was doing and made his family strong. There is Varys who knows everything about everyone. The fascinating thing about Varys is that (though he is manipulating) he actually just wants the best for the country. He saved Tyrion in season 4 because he believes that he is the only one who still genuinely wants to make everything better and who is able to do so (which is absolutely right - Go Tyrion!).
But the character I admired most for his wisdom and control over the situation while re-watching Game of Thrones is definitely Littlefinger. The more I pay attention to him, the more I realize that Littlefinger is absolutely brilliant. He predicted turns and events long before they happened. And he was always in control. Noone ever knew where his loyality lay because he was always playing on his own team instead of on one of the big houses'. Which is why he is the only character who was always in control of what he was doing, especially since the moment when he helped Sansa to escape Kingslanding.
He married her aunt, then killed her, defending Sansa, and earning her trust, just to sell her off to Ramsay. And I am sure that he knew what kind of person Ramsey was. I am actually quite certain that Littlefinger gave Sansa to Ramsey simply for the reason that he will mistreat her so badly, that she will have enough anger to re-take Winterfell with Littlefinger on his side, which is excactly what happened. Yes, this was an evil plan and his interest in Sansa is really pedophile, but he knows how the world works and I wouldn't be suprised if he still had a long way up.
And some characters I understood better now
I feel like now I understand the relationship between Cercei and Jaime and especially Jaime as a person a lot better. I always admired their relationship, not for the incest of course, but for their unconditional love and their stability which is a rare thing on Game of Thrones. But only now, that I re-watched the show, I understood that their relationship is not balanced at all. Jaime loves Cercei with all he has. She is the only woman he every loved, both emotionally and physically. And he says again and again that she is the only one who matters to him. Like, the only one. Not even his kids matter. Only Cercei.
Cercei on the other hand doesn't love quite as unconditionally. She has affairs with other men. She also repeatedly pushes Jaime away and even sends him away from Kingslanding several times. For her what matters are her children, then power, and then Jaime. Which is a huge difference to the love Jaime is giving her, and I'm sure that this will create a conflict soon.
But Jaime sill loves her. Which also makes a bit more sense of the awful scene in season 4 we all ignore. I hate this scene because 1. it's not in the books and 2. it's totally out of character for Jaime. Or so I thought. Now, that I watched the rape scene again, I realized that it's not so senseless at all. Because right before it happens, Jaime says "Why do the Gods make me love a hateful woman?" which sums up his dilemma with Cercei. She wants power and she's evil (which Jaime in his core is not) but he loves her nevertheless. And this kind of love is dangerously close to obsession. The development of Jaime and Cercei's relationship is one of the plots I am most looking forward to in season 7 because yes, Jaime does love her a lot, but we have also seen that he betrayed her once before to free Tyrion in season 4, so he's not entirely loyal.