I actually liked Uncle Tom's Cabin, but now I'm stalled out in the middle of it. I had trouble getting into A Farewell To Arms, (without a guide/class to focus my reading) and there was one at my school library that I read just so I could be the only kid to have read it: The Caine Mutiny. I struggled all the way through it, but couldn't enjoy it until the final court scene. Another one like that was The Mists of Avalon, which was just a little to feminist for a nine year old.
Whoever didn't like Tolkien because it was 'just walking': way to use the same excuse to marginalize a pillar of modern literature as every other mediocre, self absorbed teen who tries to read the Trilogy before they're ready. Read The Hobbit, take some Lit. classes and come back to it when you've matured a bit.[/fanboy rant]
Edit: No offense. It bothers me when people dislike good books because they tried them before they were capable of understanding them. It almost ruined non-Old Man and the Sea Hemmingway for me, and it scares me when the same thing happens to others.