Unfortunately, LJ's Best Books 2009: 31 Titles, Plus Best Genres & How-To doesn't have a dedicated science section but there are a few good recommendations nevertheless.
- NurtureShock: New Thinking About Children by Po Bronson & Ashley Merryman
- The Strangest Man: The Hidden Life of Paul Dirac, Mystic of the Atom by Graham Farmello
- The Age of Wonder: How the Romantic Generation Discovered the Beauty and Terror of Science by Richard Holmes
- Waiting on a Train: The Embattled Future of Passenger Rail Service--A Year Spent Riding Across America by James McCommons
- Mannahatta: A Natural History of New York City by Eric W. Sanderson
- Got Sun? Go Solar: Harness Nature's Free Energy To Heat and Power Your Grid-Tied Home by Rex A. Ewing & Doug Pratt
BTW, as I've mentioned before, if you see a Year's Best books list out there somewhere that you think I should highlight, please let me know either in the comments here or by email (jdupuis at yorku dot ca).