Oh man, so many of my favorite books are parts of series.  Harry Potter, A Song of Ice and Fire, Roddy Doyle’s Henry Smart trilogy, all of Tamora Pierce’s Tortall books.  The Harry Potter books are definitely among my favorites, but I found myself loving Tamora Pierce’s work just as much.  The Song of the Lioness and the Daughter of the Lioness duo are probably my favorites.  I really appreciate (particularly in this time of Twilight and the woman-demeaning work of Stephanie Meyer) that Pierce’s heroes are mostly women, and while they are strong, intelligent, resourceful, and noble; they also have real, profound flaws.  She also doesn’t demonize men and generally encourages mature, emotionally grounded sex (as opposed to the abstinence bullshit in Twilight and don’t even get me started on that crock of shit.)