No, she isn't. But I really like her.
It's just this thing of mine that the main character of a series or a movie as good as never happens to be my favorite character.
I don't know what it is, but it's like that. At least in most cases.
And I'm also trying to keep the number of my 'favorite characters' as small as possible.
If I added Buffy, I'd have to add for example Oz, because I like him as well.
If I added him, I'd have to add perhaps Spike and then again someone else and so on.😕
So I'll just stick with my three favorite characters Willow, Xander and Giles.🙂
But still, I like her and I don't have anything against her.
(except maybe how she acts towards the end of Season 7. I think it's in the episodes 'Empty Places' and 'Touched'. But that's it.)