I've never been a fan of Ghirahim. He came across as too much of a creeper / kind of made me uncomfortable and struck me as the kind of character you'd find in a bad yaoi fan fic. However, he did grow on me a little. His over-the-top passionate anger and his funny lines made me start liking him a bit, plus the fact that I found him challenging and fun to actually fight. He puts up a nice fight that you have to think about when you're in battle with him. I'm still not exactly a "fan" of his, but I can't... hate him as much as I'd like to, I guess, or "I don't dislike him as much as I did at first impression."
There's this little kid in The Wind Waker (Zill,I think) whom I HATED when he first showed up. He's the little boy with snot running out of his nose. That's why I disliked him. His ugly snot-glob disgusted me and the fact that he snorts it back up his nose on occasion just made my sinuses hurt and gave me a twitch. It's just a personal-squick thing, maybe because I used to have a lot of sinus issues when I was a kid and have developed a STRONG disgust / vicarious irritation-pain reaction to seeing a character snort a snot-glob up his nose. It made me mildly nauseaous. However, on secondary / tertiary playthroughs of Wind Waker, I've found that the kid doesn't bother me that much. I either got used to his habits or I decided that he was cute and funny enough as a "brat little kid" character that I stopped being annoyed by the snot. Maybe it's because I've had to mention him in fan fictions that I've written regarding the Wind Waker world and writing a tiny bit for him as Link's little friend made me start liking him. (That happens. I won't like a character until I try to explore them for fanwork and doing that makes me like them or like them more). I probably just got de-sensitized along the way, though.