I'm also a chain reader so it's hard to name individual books but I'll tell you about my favorite authors.
I grew up with Madeleine L'Engle and she's still my #1 favorite. She writes for all ages, everything from small children to teens to anthologies and autobiographies (she had SUCH an interesting, ordinary life) for adults. Oh, and poetry. Please check her out.
I still cherish my copies of The Hobbitt and the LOTR, and the Chronicles of Narnia; even though they've recently been so commercialized, the books are better.
Some of my favorite authors growing up:
Robert Cormier (cor-mee-AAY)--a pessimist; most of his books are a little sad. You may have heard of "The Chocolate War" or "The Bumblebee Flies Anyway," both made into movies
Paula Danziger--an optimist who tries to give guidance to teens and tweens through story-telling
Robert Newton Peck (I met this man and didn't like him personally but still he was a great author)--his popular books are all about a boy named Soup who gets into trouble a lot, kind of like Huck Finn or Dennis the Menace; but probably his most popular book was "A Day no Pigs Would Die" which didn't have the Soup character in it.
Richard Peck--mostly young adult books--Horror, caper, mystery, occult, social commentary, historical
Paul Zindel--wrote fiction young adult books based loosely on his own life with neglectful parents, but written with humor. However, my favorite book of his was "I Never Loved Your Mind," which would probably appeal to older teens/young adults more
Can't forget S. E. Hinton--The Outsiders, Rumblefish, Tex, and my favorite, That was Then, This is Now; many more
Catherine Gaskin--historical romance
Catherine Marshall--her bestseller was "Christy"--she wrote stories based on her families' lives
Anya Seton--historical romance
C.S. Lewis--The Chronicles of Narnia, autobiographies and religious anthologies
Robert Heinlein--a classic scifi author
Ursula K. LeGuin--fantasy; my fave was Very Far Away from Anywhere Else
Rumer Godden--children's books, poetry, fiction and nonfiction
Terry Brooks--scifi/fantasy
Maya Angelou--autobiographies and poetry
Richard Adams--an animal lover who uses animals as protagonists in most of his novels, the most famous (and one of my favorite books) being "Watership Down"
Edward Abbey--a radical environmentalist whose fictional characters are "eco-warriors" and monkeywrenchers
James Herriott--short true stories by a traveling rural veterinarian, good for bedtime stories. "All Creatures Great and Small," "All Things Bright and Beautiful"--you can easily find both these books in one volume, probably for cheap, at the big chain book stores
Some more serious true story/bibliographies that I read were "All God's Children" by Fox Butterfield (about the babyface killer and how our environment affects our character) and "Makes Me Wanna Holler" by Nathan McCall (about growing up black in the 'hood and still (or eventually, for this man) making good choices)--read this one yourself before letting your sons read it because it can be pretty graphic. We used to give this book to students in a program I worked for but we ripped out the chapter titled "Trains" first.
A book I think everyone should read is "The Children's Story" by James Clavell.
It's hard to stop but I'll force myself here.
FYI, at least here in OK, on Black Friday, Half-Price Books is opening at 7 a.m. and giving book bags and $5 gift certificates to the first 100 people, with one person getting a $100 gift certificate.
Also, check out your local "Friends of the Library" chapter to see if and when they host book sales. I've picked up great books for as little as ten cents at these sales.
If you want more book titles, message me and I'll make a list from my bookshelves :)