Vivienne: met my expectations, I did not think I would like her, and in my first playthrough, well, she full on hated me until I managed to get her into an uncaring neutral. I can still appreciate her character, however. In this instance, I miss the DA2 rivalry system, where I really would have loved to be rivals with Vivienne, while still remaining amicable.
Varric: As much as I loved him in DA2 -and he was my favorite character in that game- in DAI I just found him to be rather..bland. I knew that he would never be as close with the Inquisitor as he had been with Hawke, and that he would be more grim. But his personality just came across as more stale than bitter, which I think I would have actually preferred, because at least it's something. I still love Varric, of course, but had I only known him for this game, I likely would not have connected much.
Dorian: I underestimated my love for this character pre-game, he easily became one of my favorite characters in the series. I laugh at nearly everything he says, and I loved the emotional moments he had in his personal quest, the voice acting was wonderful.
Iron Bull: I thought I would end up liking him much more than I did. Not that I disliked him or anything, I just never quite connected. I feel as though many of our conversations, especially at the beginning, are too formal, rather than friendly.
Leliana: Definitely surprised me the most. She was one of my favorite characters in DAO, and the entire game I just felt so incredibly..sad for her. Of course, I made the mistake of accidentally hardening her at the beginning, and playing through her personal quest was, surprisingly, the saddest moment in the game for me (given, I didn't have a Warden Alistair or Loghain import, so it didn't have much to compete with.) But, I wouldn't actually care if she brutally murdered people, while still remaining perfectly happy, (that is what the majority of our companions do, after all) but you can just tell how incredibly miserable she is inside, and it broke my heart.
Sera: What a surprise for me. I didn't think I would like her at all, she came across as having a very black and white view of the world in the early previews, and well, she does. Along with not liking elves or mages (I was an elf mage by the way.) She's also extremely immature and I really don't agree with her about anything, even remotely. And yet.. I just love her. I have no idea what it is, maybe it's because I tend not to really take her seriously, but I think she's probably my favorite female companion in Inquisition. She isn't the type I'd have a heart-to-heart with, but I loved spending time with her.
Cole: I knew I would love Cole from the start, and he lived up to all of my expectations. I didn't like the way he seemed to see the world in black and white at first, kind of like Sera,"bad things should happen to bad people," but I really love the way this changes when you take the human path. Before reaching that quest, I was almost certain I would choose him as a spirit instead, but having seen both versions, I completely prefer human. Perhaps it's because as a human, he has flaws, and flaws are what makes me love these characters.
Blackwall: I was the least interested in him pre-release, and that remained the same. Something about him is just so dull, even with his personal quest, which you'd think would make him interesting. I really want to give him a try, and I do like him slightly more on my second playthrough (although he still calls me a criminal after getting him out of jail, yeah thanks.) Like Varric says, he's just like Sebastian. He's my least favorite character, not because I dislike him in the slightest, he just doesn't add anything to the story.
Solas: I knew I would love and I did. Being open-minded and having a 'shades of grey' type of perception are traits I love in both people and characters. But wow, was he unexpected. I thought he would be shy and socially awkward, having lived away from society. But instead, he's highly confident and clearly socially skilled, he's even rather an elitist at times, and condescending when you don't agree with him, which makes since once you know the reveal, but definitely unexpected. Most of all, he's just really unknown, you can tell that his polite persona certainly doesn't match up to the malicious smirks he gives you off-screen, along with his reputation, which is likely at least part-true. He's the mysterious Morrigan-like character that I've been craving, but that he is was completely unexpected.