It's probably because I don't know what was considered fashionable in the '90s, so I can't really comment on it, but I do think that she looked the best in the third season with her shorter curly hair. With how much her character seemed to have changed at the start of season 4 (in my view, anyway), she almost felt less Andrea-ish with her straight hair, especially when she went blonde.

I know it probably seems silly to go on about hairstyles and outfits, but I just feel as though I liked her character the most this season, and I think the way she looks kind of represents her positive transformation into a confident young woman.