Two of the first free books I picked up were Dracula and Frankenstein. They weren't the best kindleizations (no chapter book marks) but they were readable. Alice's Adventures in Wonderland/Through the looking glass we're worse because several of the poems and stories within the story were stripped out. Leaves of Grass was completely unreadable.

I have a free e-book blog in my RSS reader. However 95% of what's offered for free is crap, with reviews starting with the words, "Christian publishing house..." Gems can be found if you're willing to wade through the muck.