Ooh, tough one.
Alison,
Claire, and
Charlotte are all such good names.
Claire is about as popular as
Charlotte, just on a slower curve up. Both those are totally not-too-popular classics, never really totally out of style, but
Charlotte seems trendier.
Alice is on a steep curve up, and was much more common for longer in the past. I still think of it as dated and dowdy, and I don't like it, but
Charlotte and
Claire never even seemed dated that way for me.
Alison will probably seem the most like it's too old for her when she is grown, and that's the only reason I'd be inclined to strike it off. So I'm voting for
Charlotte, second place to
Claire.
May I suggest
Caroline too? It fits the not-too-popular classic profile, and seems to have the sounds you like.
Personal impressions: they all sound smart ..
Alison - independent, softspoken, least likely of any of them to seem stuckup.
Charlotte - reserved, feminine
Claire - it reminds me of the word flair so there's that. Tidy too, maybe clipped.