What is your favorite book now? ...10 years ago? ...20 years ago?
This is tough, I'm not good with favorites. Empirically probably Lord of the Rings, simply because I keep picking it up to look up a reference and getting sucked in to reading a good chunk of it over again. It's certainly one I would miss if I suddenly became unable to read it again.
What book made you cry?
In a good way: Connie Willis is good at this. I'm frustrated because I know I was just reading something that made me weep a week or two ago, and I can't recall what it was. Ursula LeGuin's short stories often get me, too.
In a bad way: The Culture of Make-Believe by Derrick Jensen - in trying to examine the roots of cruelty and slavery he looks under some pretty nasty rocks.
What book shocked you? I guess maybe the second part of the previous answer could/should be moved here...
What book have you thrown across the room?
Something by Nietzsche, I recall at one point. I remember throwing (or having the urge to throw) a number of books my first year in grad school - probably history of science stuff - but not, strictly speaking, exactly what they were. Argh.
What book were you unable to finish?
That I'm still trying to read? The Gulag Archipelago, and I'm still working on it.
What book did you like once, but now can't stand?
Anything by Anne McCaffrey, but especially the Dragonrider books. Ok, can't stand is a bit strong for the old stuff, but I haven't been able to read anything she's written since around the time of Masterharper of Pern.
What book most made your life what it is today?
The sad answer is probably the corpus of Heinlein's work, especially the Future History collection of stories. An answer I'm slightly more proud of would be Emma Goldman's autobiography Living My Life.
What book would you most like to see adapted to film?
Borge's "The Garden of Forking Paths" from The Labyrinth - if it's cheating to choose a short story, too bad.
What is your favorite book by your favorite author?
Against A Dark Background, Iain M. Banks - though this item is subject to change without notice.
What book must you really read someday?
I'd like to take another stab at Gravity's Rainbow, I think.
What's on top of the nearest to-read pile?
Beowulf, the Heaney translation
What book made you want to jump off a bridge?
The LDS scriptural works (King James Bible, Book of Mormon, Doctrine & Covenants, Pearl of Great Price). No, I'm completely serious. You try reconciling being told that your only way to true happiness is the absolute stuff of your worst nightmares. The only thing that kept me from jumping off a bridge for the most part was the remote possibility that the afterlife was as described by the works in question, where I would be equally miserable...
What book made you want to write?
Piers Anthony, as in realizing "Holy crap, I can write better than this!!"
Oh, well if you want a positive influence/inspiration, probably learning when I was a small child that my grandmother had a short story published. And the Margurete Henry books about horses, though I couldn't tell you why those made me want to write, other than the impluse that makes people write fan fiction - wanting more of a particular type of story, I guess.
What book changed you?
The Introvert Advantage by Marti Laney. I don't hate people, I just hate being around them.
What was the first book you bought?
I honestly can't remember. Too many, too long ago.
What was the most recent book you bought?
I think Alan Moore: Portrait of an Extraordinary Gentleman
What book do you think more people should read (i.e. run around shoving copies of into people's hands, say)?
The Wasp Factory, Iain Banks. It's good, it's short, and if you know where to look you can see the crystalized seeds of all of his major themes... and it's his first published work, iirc.