I like Environmental literature, atm I'm reading The Skeptical Environmentalists which is about the exaggeration and true representation of statistical data in the environmental field - as BOTH sides are liable to over exaggerate.
Prior to that I read The world according to Pimm: A scientist audits the earth, which is all about quantifying our resources and challenging the outdated mentality of 'limitless bounty' (ie natural resources, typified by the amazon or the image of the open oceans in the 19th c.)
I like anything to do with nature.
Bill Brysons a walk through the woods was a good modern shout,
Gary Snyders writings are awesome too, especially if you like poetry - but his long essays are great.
I also like reading 'challenging' books outdoors as there are less distractions, recently read Zen Mind, Beginners Mind, by S Suzuki, being inna is a good setting for this kind of book
