Okay. I can play along. Somewhat. ;)
1) The Pern Series, by Anne McCaffrey - This is the series that made me completely fall in love with fantasy, dragons, and the eternal struggle to form a more perfect society. There are MANY books in it, with a few tangent story lines and mini-trilogies. They're all worth it. It's the most complete and detailed other-world adventure I've ever found, and led me to years of online role-playing games based on Pern.
2) The Harry Potter Books, by J.K. Rowling - I've always said that I may be getting older, but I refuse to grow up. See, I'm just cleverly disguised as an adult. And I give bigtime kudos to anyone who can give kids (of all ages) a passion for reading again.
3) Druids, by Morgan LLywelyn - A friend gave me this several years ago, and I recently bought my own copy to re-read it. It's a historical fiction piece about the struggle of Celt vs. Roman in Gaul, as told from the perspective of Ainvar, who becomes Chief Druid of the Carnutes and Keeper of the Sacred Grove. Fun, controversial, and well-written. Besides, Anne McCaffrey called it "Splendid and compelling," which was enough for me to pick it up.
4) The Encyclopedia Brown Series, by Donald Sobel - Another series of books for young readers, but a lot of fun. I admit that it's been some time since I've read any of these, but they were such fun! He's a kid detective who solves cases large and small using common sense, deductive reasoning, and one tiny detail. It's kinda like Harry Potter meets Murder She Wrote meets Monk. Even as an adult, it's fun to try to solve the case with or before Encylopedia Brown. Definitely a reason I love crime dramas and who-dunnits today.
5) Lady Audley's Secret, by Mary Elizabeth Braddon - A fine Victorian serial novel. I read this one for my Brit Lit II (and Gender and Humanities) class. and actually loved it. It's unlike most Victorian novels because it was published as a serial. This means the action starts right away and keeps going throughout the book. Unlike most things by Jane Austen or Charles Dickens (who were paid by the word), there isn't a 4 page description of a field of grass. It's a murder mystery of sorts, and is really quite good.
6) The Snow Garden, by Christopher Rice - Yup, Anne Rice's gay son is an author, and a damned fine one at that! His tale of murder and intrigue holds you fast with realistic characters, scandal, and secretive pasts. Every character has something to hide, each plot twist is miraculously connected, and the tension is nothing if not taut. Loaned to me by a friend at work, I read this last Fall. I don't do enough reading for fun, so this still makes the list.