Let's see...no order whatsoever...
Traveling Mercies by Anne Lamott
[I'm actually in the middle of it right now, but I'm pretty sure this book might just save my faith. Regardless of what you believe, however, she's a great writer and her stories are above all honest, then touching. Definitely my recommendation for those interested in looking at a positive side to modern Christianity.]
If I'm going to list that, then I should probably list
The Irresistable Revolution by Shane Claiborne
[Especially for Christians, this book is a few hundred pages of the most uncomfortable, yet convicting, prose you will ever read. This is the story of a movement to recapture the idea of community that a culture of wealth has lost...by rejecting wealth. Again, a great (and probably unexpected) voice coming out of modern Christianity.]
Heh. Those, and
A Brief History of Time / The Universe in a Nutshell by Stephen Hawking
[Made me think in ways I hadn't ever thought of thinking in before. My mind went - boom!]
Something Wicked This Way Comes by Ray Bradbury
[He writes so...beautifully. Egad. The way he used words in this book really made a connection with me.]
Count Zero by William Gibson
[Count Zero is probably my favorite book of his, but Neuromancer, Mona Lisa Overdrive, All Tomorrow's Parties, the man's entire body of work is just awesome. I love him so, so much.]
...
Should be on the list, but not enough space: Against a Dark Background by Iain Banks. Exceedingly dark, but excellent fiction. The ending left me with a void in my gut and a chill down my spine, and all I wanted to do was throw my fist up in the air in the emptiest feeling of triumph I've ever felt. So strange, but so good.