heyyy, ginger snaps was my first thought also !!! definitely my fave 'coming of age' type horror movie, and one of the best from the 2000s.
other movies from that period i really like are ichi the killer, the o.g. saw movie, and behind the mask: the rise of leslie vernon! and this is cheating a lil bit cause its from 1996 technically, but the craft (dir. andrew fleming) feels like a spiritual predecessor to sooo many of the good 00s horror flicks such as ginger snaps, jennifer's body, & may.