My top 5 science books:
Origin of Species, by Charles Darwin. Whether fundy, atheist or disintrested party, read this book. You’ll then at least know (a) what the argument is about, and (b) not make the same few stupid mistakes when talking about the subject.
The Mismeasure of Man, by Stephen J. Gould. Learn how easily science can be, and has been, abused.
Gaia, by James Lovelock. Not hard science, but a genuinely intriguing book. One that’ll make you think.
Fads and Fallacies in the Name of Science, by Martin Gardner. Learn why pseudoscience is bad, but occasionally very, very funny!
The Feynman Lectures on Physics, (or anything else) by Richard P. Feynman. The guy’s a genius, period.