YA: I hear Jane Yolen has done some awesome YA books. For as much of a fan of Neil Gaiman I am, I only have Coraline. Frank Beddor's series was awesome. Scott Westerfield's series (Uglies, Pretties, Specials, Extras) was pretty good too.

Fiction: I /love/ retold fairy tales. Have been looking for Ellen Datlow's Tamsin tale.. and will be adding some of her edited books to my amazon wishlist. Charles de Lint is also an awesome writer. (again, see wishlist.) I would like to find the other two books of his where he published originally under the name Samuel M. Key (I've got Angel of Screams.) Nancy Madore has an erotic fairy tale collection called Enchanted, which I have, but there's another out there that I want. I'm also a fan of Jacqueline Carey and am missing the third book in the second Kusheline trilogy. (which must be hardback to match the others in the set.) Oh, I also like Diana Gabaldon, and have read (but do not own) through to the newest Echo In The Bone. Nor have I read the spinoffs featuring Lord John Grey.

Alternate history intrigues me, although with the exception of Gregory Key, haven't read any.

SF: This is a bit trickier. I like Harlan Ellison, Ray Bradbury, and Roger Zelazny (although I've only read his Amber series). I like reading my dad's Analog magazine when I can get my fingers on it. However, other than the above mentioned authors, I can't help you much.