There are actually many reasons I liked Wishful Thinking, but as Hazel only gets three wishes I felt I should limit my list to three specifics.
1. The ending: Yes, I know I am beginning my list with the ending, but it was my favorite part. The end of the novel did not just wrap everything up all neat and tidy. I like a happy ending as much as the next person, but it is just not realistic all the time. Hazel's story progressed as it should without contrivances and false plot elements. I like its authenticity, yes, I said authenticity, despite it being a fantasy novel. The fantasy elements are simply the vehicle for Hazel's search for identity. It is even more authentic as she is the only one who knows what is really going on so the other characters simply accept her as she is.
2. Adoption: While this is not the first book to address the topic of adoption, it is the first I have read recently, in which the adoptee does not have faery blood. (It is a nice change.) Hazel is entirely human, and at age 17 looking for some answers about her biological identity, lamenting her difficult life as a adoptee. She is given a unique opportunity to have some of her questions about herself answered, then return to her life a bit wiser and more mature...maybe cliché, but well done.
3. Hazel: I just really liked her. I was rooting for her the whole time and I wanted it all to work out for her, and though it did not turn out how she or I thought it would, she handled it with grace, maturity, and love. She is someone I would like to know.