I'm a big fan of Alamut by Bartol(?). Similar to Lord of the Rings but without the bore. Michael Crighton has some good ones: Sphere, Congo, Jurassic Park, Next. However, most of his other stuff is boring. A book I've enjoyed particularly is Rumo and His Miraculous Adventures (really cheesy but a good read). And, of course, there is Edward Bellamy's Looking Backward and what's-his-name's 1984, two strikingly different views on the course of history and where it is leading us (the first is a little boring at times).
But the best book ever is: East of Eden by John Steinbeck. Easily. I had to read the book for class (4 books by any one author in a school year), but the library didn't have it forever. The day of the test, it came in, but of course it was too late. Still, I read the book, starting at 4:00 in the afternoon, when I got home from school. After all, I would have to write an essay on the book the next week. 11 hours later, I finished, skipping food, water, and a shower to finish easily the best book I have ever read. I didn't notice time moving by. It was that good. But then again, I'm kind of a girly man...Still, most stuff by Steinbeck is short and entertaining. Just don't read the Grapes of Wrath. It is one of the most boring, repetitive, and just plain dull books ever considered a classic. Of Mice and Men, Cannery Row, Tortilla Flat, and East of Eden (off the top of my head) are much better books and so much less boring.