Non-fiction:
Let the Dog Decide - perhaps best training book on dogs I've ever read, and enormously helpful with my Saint Bernard/Great Dane sire and my Great Dane bitch.
The Intelligent Investor - I'm rereading Benjamin Graham's great book every couple of years.
Human Anatomy: the Beauty of Form and Function - a great lecture series on anatomy I just finished. I was using it as a lab reference for homeschooling the kids but liked it so well I listened to it myself. It was professor Young at Howard.
Cook: The Extraordinary Voyages of Captain James Cook - I try to read at least one biogas every reading cycle. Biographies are invaluable reference sources for understanding human behavior, as well as history. This is a good one about Cook.
Fiction:
I just finished Jim Butcher's Fool Moon. To me, and I like the Dresden books, it was his least interesting book, being little more than a "monster fight." No Dick work, no real magic, not much psychologically interesting. Instead it was little more than a stand-up slugfest. (Don't get me wrong, it was a good slugfest and I like an occasional slugfest.) So the book was his least interesting read, but, it was also one of the more viscerally exciting. Because the fights were something out of a comic book, beat the hell outta each other, get close to being killed several times, exhausted, think can't go on anymore, do so anyways. I like a guy who won't lay down even though he should be dead. It was not an interesting book, but it was very exciting.
The Horror Stories of Robert E. Howard - He was no Lovecraft when it came to horror but he could sometimes be just plain weird, creepy, and enjoyable to read.
For my literature reading I'm rereading The Idiot. I love reading Russian writers and poets, Tolstoy being my favorite, but I alos like Dostoevskii, Pushkin, Chekhov, etc.