The best fantasy for girls would depend on what kind of fantasy the girl is interested in. For example, if she enjoys stories with strong female protagonists, then fantasy books such as The Chronicles of Narnia, Harry Potter, and The Hunger Games would be great choices. If she prefers more light-hearted fantasy stories, then books like Alice in Wonderland, The Wizard of Oz, and Charlotte's Web would be better options. Ultimately, it all depends on what the girl is looking for in a fantasy story.