First Plays by A.A. Milne

Amazon | Project Gutenberg
This volume includes five delightful, witty early plays—three one-act plays, including "Wurzel-Flummery," in which a rich man's bequest comes with an eccentric condition; and two three-act plays, including "The Lucky One," which contains the most real drama out of the lot. (Don't miss Milne's introduction, which is just as entertaining as the plays themselves.)

Childe Harold's Pilgrimage by Lord Byron

Amazon | Project Gutenberg

In the deep umbrage of a green hill's shade,

Which shows a distant prospect far away

Of busy cities, now in vain displayed,

For they can lure no further; and the ray

Of a bright sun can make sufficient holiday.

A long narrative poem, in which the travels of its protagonist give the poet the opportunity to describe and muse upon the landscape of the countries he travels through and historical events that took place there.

The Hound of the Baskervilles by Arthur Conan Doyle

Project Gutenberg
Perhaps the best of Conan Doyle's novels featuring Sherlock Holmes, The Hound of the Baskervilles finds the famed detective investigating the mysterious death of a baronet at his Dartmoor estate, tied to a family legend involving a ghostly hound—and a very real danger that may threaten the new heir.

A free edition is not currently available directly for Kindle.

Hans Brinker, Or, The Silver Skates by Mary Mapes Dodge

Amazon | Project Gutenberg
Hans and Gretel Brinker dream of entering the great skating race with a pair of silver skates as prize, but with their invalid father, who lost his memory in an accident years ago, unable to work, they are too poor to buy skates of their own to enter. Meanwhile, a group of boys from the neighborhood embark on a skating trip to the capital city of Holland, and eventually their adventures intersect for a happy finale. A lively, funny, heartwarming children's classic you won't forget!

Mother by Kathleen Norris

Amazon | Project Gutenberg
In this lovely, heartfelt story, Margaret Paget, a young woman discontented with the small-town life of her large family, leaves for the city in search of wealth and culture and a career—only to learn, when she needs the knowledge most, to appreciate her own hardworking mother and the beauty of the home life her mother has created.

This is the original, unedited edition; recent print editions have altered the text in different ways.

The Pilgrim's Progress by John Bunyan

Amazon | Project Gutenberg
John Bunyan's timeless allegory of the Christian life, told through the story of Christian and his journey to the Celestial City. The editions I've linked to are Volume I only, in Bunyan's original language—there are free ebooks of the 1909 edition with updated English on both Amazon and Project Gutenberg, which also include Volume II, the journey of Christian's wife Christiana and her children.

I have not personally read the ebook editions all the way through, so if anyone reads them and finds significant formatting problems, please do let me know.

Chip of the Flying U by B.M. Bower

Amazon | Project Gutenberg
The cowboys of the Flying U ranch are initially dismayed to learn that their employer's sister Della, a young lady doctor, is coming to visit. But Della quickly charms them all, and forms a sometimes tempestuous friendship with cowboy Chip Bennet, whom she encourages to develop his hidden artist's talent. A lively, charming romantic comedy, with an authentic feel for Montana ranch life at the turn of the century.

My review of this book.

Treasure Island by Robert Louis Stevenson

Amazon | Project Gutenberg
A beloved adventure novel and probably the most famous pirate story ever written—with good reason! When a map to pirate treasure unexpectedly falls into the hands of young Jim Hawkins, he becomes part of a voyage to retrieve it—a voyage that turns into a dangerous adventure of mutiny and battles with the pirates who are also determined to get their hands on the treasure.