(shiver in delight, by the way)
Shiver 1. Hush hush! Secrets, I love secrets! I also love conspiracy theories. The fact of it is, when a book is able to surprise me with a secret I wasn't able to figure out and wouldn't have guessed, I love it. Not like a deus ex machina, but more of a plot-twistish thing. It adds so much to a story, when used correctly, and gives me the shivers.
Shiver 2. Cool bad guys. I mean it - so often, the books I read feature cardboard cutouts instead of actual, living beings. And the other books I read are so desperate to avoid their bad guys being cardboard that they make them wimpy, or mild-mannered, or try to make them seem good, but misguided. I love it when bad guys are unique, understandable, and undeniably badass (sorry, anyone from church who's reading this! - and sorry mom.) There's definitely an issue with bad guys who just want to take over the world and never actually give a reason why, but does every villian have to be 'misunderstood?"
Coolest Bad Guys Ever -
Lestat, as protrayed in Anne Rice's Interview with a Vampire. He has a past, he's legitimate, and he does his most awful acts (turning an innocent child, later allowing that child to be killed) as casually as he drinks his tea. And he even takes the time to defend himself in other novels, making him out to be fun, if vain. Is the truth in those other novels genuine? It's just as enjoyable to imagine the 'evil' Lestat is believing himself a good guy as to imagine he's genuinely telling the truth.
Screwtape, from C.S. Lewis' The Screwtape Letters. He doesn't actually do anything, but he's so good at what he does (see Shiver #5) and he's amusing while he does it. Shere Khan-esk desire to 'eat' the hero alive, and needs no sympathetic backstory.
Shiver 3. The Inevitable Conflict - most books have this. The free-spirited princess who refuses to give up her dreams and marry, the two countries on the brink of war, the old childhood enemy with a chip on his shoulder. Here's where it can go wrong: when it magically disappears (wimp-out) or when it's dragged on too long. It can last the whole book, but only if it's a big enough problem. When the inevitable conflict is solved in a page or two, I always ask, "Well, why didn't they just solve it three hundred pages ago?"
Shiver 4. The Inevitable Conflict meets the Secret - oooooooooooooooooOOOOOOOoooooooo.
Shiver 5. The Perfect Fit. The compitence of someone who was born to do something - and the awesomeness they achieve when they do it. Often, this is done unrealistically, but I believe that it happens in real life, and can happen in fiction. And when it's done well? *shivers*