Free books needn't mean crap books, just download out-of-copyright stuff. The 19th century produced nearly all the books that are set works nowadays. In the last few years I've read many classics that I'd missed previously, including
Tolstoy: War and Peace, Anna Karenina
Dostoyevsky: The Idiot, The Brothers Karamazov, The Gambler, Crime and Punishment
Brontes: All the books by all the sisters, had only read half of them before.
Samuel Butler: The Way of All Flesh. Erewhon, Erewhon Revisited.
Joseph Conrad: The Heart of Darkness, currently reading "Under Western Eyes."
Edith Wharton: The House of Mirth
Somerset Maugham: Of Human Bondage
David Lindsay: A Voyage to Arcturus (1920's Science Fiction by a first world war veteran.)
That's just the ones I remember off the top of my head.
Now that I think about it, I'm lying about Tolstoy, I read that in paperback, the free editions wouldn't have footnotes translating the French the characters speak to each other, I have no French so would have been lost without footnotes, which my free editions don't have.
I actually had read Heart of Darkness more than once before, but a few days ago DD was fiddling with reader and managed to leave it open in that, I read from there and then re-read the whole book and it a completely different experience from the previous times I read it, I think this is the first time I've managed to slow down and really take in the deliberately dense writing. Someone needs to make a impressionistic over-the-top film to really try and capture it. ("Apocalypse Now" was over-the-top but realistic.)
I have a hundred or so free classics I haven't read before queued up on my reader, lots more on the internet when those are read.