How about that one about the Golden Braid. It’s held up as the intriguing book none of my friends can get through (I haven’t tried)!
Not long ago I read the earliest great work of literature in the world, the Epic of Gilgamesh. Although the title “epic” sounds intimidating, it actually can be read in one uninterrupted day. The modern translation I had was 110 pages. Gilgamesh is a godlike warrior-king of ancient Sumeria (in modern-day Iraq) who tests himself to the limit, and is humbled by his hubris. The story has it all: sex, violence, monsters, a mystical journey to the underworld, and the bitter wisdom of experience. And a subplot with some intriguing parallels to the flood story in Genesis!
Other books I’ve loved:
• The short stories of Ernest Hemingway
• Lolita, by Nabokov
• The Meditations of Marcus Aurelius (get a modern translation)
Two books of essays by David Foster Wallace:
A Supposedly Fun Thing I’ll Never Do Again and Consider the Lobster. His writing is beautiful, thoughtful, funny, challenging, weird, amazing, and best of all, really dense. Trust me, both of these modest volumes will last you two years–and it’ll be worth every minute.
Oops–I forgot to add that Wallace was a math guy first, so his writing is math-influenced in a very interesting (i.e., not boring) way.
He has another book that I own but haven’t read that is supposed to be very interesting to both mathy and non-mathy types: Everything and More: A Compact History of Infinity. Like the other two I mentioned, it’s a slim volume and won’t clog up your bags.
Some non-fiction books I’ve read since coming to college (both for class and for fun) are below. I’m an English major, so I hope these are interesting to you.
Regarding the Pain of Others by Susan Sontag–I sold my copy of this when I was done with the semester, and I really wish I hadn’t. Lots of things to chew on regarding the space created by the media between actual catastrophic events and the viewer.
The Fifties by David Halberstam–An analysis of the decade, basically. Very, very interesting, especially if you’re reading it in conjunction with some literature of the period (Flannery O’Connor, Truman Capote, Jack Kerouac, etc.)
A Mind of Its Own: A cultural history of the penis by David Friedman–Most of what I’ve studied so far has been 19th-century women’s lit, and there isn’t much penis in that, so this book was an eye-opener regarding attitudes towards the penis and masculinity through history. Actually very light and entertaining.
History of Ideas on Women edited by Rosemary Agonito–A collection of essays written about women from Genesis to the United Nations’ Declaration of Women’s Rights.
From the Beast to the Blonde by Marina Werner–This plus a copy of the Brothers Grimm complete stories, one of Andrew Lang’s fairy books, a Joseph Jacobs compilation, and The Canterbury Tales ought to keep you busy for a while.
Best of luck!
I wouldn’t really consider myself a reader, and I definitely am not a science fiction fan, but the SDMB turned me on to Neal Stephenson who is a sci-fi writer but has written some totally fascinating books.
I highly recommend the Baroque Cycle by Stephenson which is three large books: Quicksilver, The Confusion and System of the World.
I suppose it’d be considered historical fiction, in that the main (fictional) character meets up with real historical figures and experiences real historical events. You get to learn about Newton and the Royal Society, pirates, European Royalty, the introduction of world currency and banks, and tons of other stuff that I never knew about before. And it’s just plain nerdy fun.
I think as a scientist you’d like it. I liked it because I have a curious mind - and you do too. So you’d like that aspect as well.
And while you’re picking up your Stephenson check out Cryptonomicon too because it’s a sort of prequel-but-sequel. I read that before the Cycle, and it came out before the Cycle, but it happens many years after the Cycle (but has some common characters).
Those 4 books would hole you 4 months 
All three volumes (3000 or so pages) of A Civil War: A Narrative by Shelby Foote. Extrememly readable and engrossing.