Why the Straight Dope series, what else. One volume by the stool, one at the bedside.
Why has it been so long since the last of the series came out?
Before: The Lord of the Rings trilogy and Silmarillon, Moby Dick, most Wambaugh police books, three of Michener’s, Clear and Present Danger, Dune 1, Defeat in the West, Samurai, Panzer Leader.
Now: Harry Potter 1-7, Illiad, Decline and Fall of the Roman Empire, Autumn Lightning.
Several of the Heinlein “juveniles”: Have Space Suit—Will Travel, Between Planets, Tunnel in the Sky, Red Planet, Rocketship Galileo.
SM Stirling’s Island in the Sea of Time trilogy.
A few Dean Koontz novels: Phantoms, Strangers, Coldfire, Twilight Eyes.
Ariel by Steven Boyett
Hardwired, Voice of the Whirlwind and Days of Atonement by Walter Jon Williams.
I have read Watership Down probably dozens of times.
Like Amateur Barbarian, I have read and reread the Travis McGee series a few times. I read them as I found them in the beginning, went back and read them in order, and I will pick one up now and then to read still. I just happen to have started on A Purple Place for Dying a couple of days ago. Have them all, except for A Deadly Shade of Gold, on my bookshelf.
I have read Michael Ondaatje’s In the Skin of a Lion a few times and will likely pick it up again.
I also go back to Margery Allingham’s Albert Campion books time after time. Love the way she writes and how she can pack so much story into a few sentences.
Lord of the Rings trilogy - I have and will read it from cover to cover every year or two until I die. I am instantly transported into another world, all fades away.
Gone With the Wind - many times, there’s always some new little thing I notice.
At Home - nonfiction, by Bill Bryson. Fascinating story of the history of the house.
Square Meals - Jane and Michael Stern. A retro cookbook featuring recipes from the 20’s through the 50’s, written in their own inimitable style. So droll, so soothing, and such good home-cooking type recipes!
Encyclopedia of Country Living - Carla Emery. A huge pulpy non-fiction compendium on how to live out in the country on that homestead, like a hippie/pioneer/farmer. From buying land to planting a kitchen garden to slaughtering a steer, plus lots of Erma Bombeck-ish family stuff in between chapters.
I’ve read several Uncle John’s Bathroom Readers from cover to cover, you have to really LOVE reading, there is so much in them, and so many of them.
Many, many books; too many to list. I’ve worn out several copies of Earth Abides.
The Razor’s Edge
Of Human Bondage
Siddhartha.
Zen and the Art of Motorcycle Maintenance
World of Jeeves
Ready Player One - Ernest Cline
The Rook - David O’Malley
Point of Impact - Stephen Hunter
Lawrence Block’s Hitman and Burglar series.
Ursula K. LeGuin’s Earthsea trilogy. If I were condemned to have only one book to read, ever, it would be the third book in the trilogy, “The Farthest Shore.”
Jack Vance. ANYTHING by Jack Vance! I’ve reread his stuff uncountable times. The man is (was) amazing. His style is unique, and I adore it.
Alice in Wonderland and Through the Looking Glass. Classics, and deservedly so. Some of the most quotable literature in history. (“Why, sometimes I’ve believed as many as six impossible things before breakfast.”)
I’m an inveterate re-reader - Pratchett, Niven, Heinlein and Varley are some of the authors I return to regularly.
The Hitchhiker’s Guide to the Galaxy is probably my most-read book & (to a lesser extent) the sequels as well as both Dirk Gently books. In fact, I think I’m due for a re-read of the whole shebang… 
Kurt Vonnegut - Cat’s Cradle and Sirens of Titan the most often; have read most of his other works at least once or twice.
I was completely hooked by the first few paragraphs of Curse of Chalion in a way that is very rare. I’ll definitely revisit it. Too bad I haven’t been able to get it up for the sequel. I’ll have to check out other Bujold stuff though!
I always go back to Hitchhiker’s Guide, Pride and Prejudice, Persuasion, Anansi Boys, Good Omens, A Night in the Lonesome October, and my favorite HP Lovecraft stories.
Hunter Thompson, some of Vonnegut’s stuff, certainly Brave New World, some Stephen King favorites.
Heinlein: The Moon Is a Harsh Mistress.
Heinlein: Time Enough for Love.
Hugo: Les Misérables.
Rand: The Fountainhead.
Rand: Atlas Shrugged.
Boorstin: The Creators.
Hofstadter: Gödel, Escher, Bach.
Clarke: Childhood’s End.
And a new one:
Levitin: This Is Your Brain on Music.
One Flew Over The Cuckoo’s Nest.
I have a lot of Stephen King, Clive Barker, and H.P. Lovecraft that I read repeatedly, but Cuckoo’s Nest is the one that I read a few times every year without fail.
I love that book.
Kim by Rudyard Kipling. Awesome book. I take it with me on business trips (I have a lot). There are many different parts that I reread and sometimes the whole thing. I have to read to sleep, and there’s always some dead time in transit, and if I’m stuck on a flight with nothing to do then it’s right there.
A Prayer for Owen Meany
Larry Niven (Ringworld, Ringworld Engineers, Protector)
Stephen King (Misery, Salem’s Lot, etc.)
Michael Moorcock (the Corum Swords Trilogy, the Chronicle of the Runestaff)
I’ve only read it twice… Time for another go!
Have you read any Talbot Mundy? (Many of his books are free on Project Gutenberg, including a trove on gutenberg.net.au. Why the Ozzies have books of his that we Yanks don’t, I dunno.) I like to describe Mundy as an Americanized low-calorie Kipling. You might enjoy “Guns of the Gods.”
Had Kipling written it, it would have been much more harum-scarum, gung-ho, over-the-top adventurific. Mundy is more sotto voce. But, doggone, I do love him!
I don’t reread much, but have done multiple readings of Josephine Tey’s The Daughter of Time, Yann Martel’s* Life of Pi*, and John Irving’s Cider House Rules. I also finally forgot the plots of all the Agatha Christie books I read as a teen and enjoyed reading all those again over the past couple of years.
Lots and lots of the Discworld series by Terry Pratchett. Each time, I discover some new level of humor and depth in his writing.
Another one for the Harry Potter books, too. I don’t quite know what it is about them; they’re kind of like potato chips - almost addicting. I think it has to do with the way she writes dialogue. The way conversations ebb and flow just sounds really natural. It’s something I’ve never really found in other novels, no matter how much more highly regarded they are than hers.