This is a completely biased list, based on the books I read in 2010, and based on only my opinion. And I am lumping various sub-genres together under their main category (i.e. all kinds of Fantasy go under Fantasy)
The Great Gatsby - F. Scott Fitzgerald
Execution Dock - Anne Perry
Anansi Boys - Neil Gaiman
Love Story - Erich Segal
The Diary of a Young Girl - Anne Frank
Proust was a Neuroscientist - Jonah Lehrer
Best Science Fiction - It's a TIE
Journey Into Space - Toby Litt
Fountains of Paradise - Arthur C. Clarke
I don't make a habit of abandoning half-read books, and I don't list them on my book list, because if it is not finished, it doesn't count as read. But I wanted to keep track of the ones I abandoned, and why.
Next - Michael Crichton (at about page 150).
This had a good premise. I really would have liked to read this story, and if it was a movie, I would have enjoyed it. But the writing was just a torture. I get it that we need more than usual amount of exposition for science-heavy subjects, but this goes beyond torture, and a lot of it quite frankly was unnecessary. A thriller is supposed to be...well...thrilling. You shouldn't be able to put it down. It should be fast paced read, not something that makes you feel like you are sitting in a science class with a droning teacher. So I finally gave up.