Well, The Harry Potter books run about 700+ pages each, and are pretty interesting.
I also highly recommend Memoirs of a Geisha, both for it's story and because it destroys the popular misconceptions about Geisha being prostitutes. I think it goes to about 430+ pages.
Also, as far as 150-200 page books go, I'd recommend going old school, with Animorphs, Goosebumps and of course, my favorites: The Chronicles of Narnia.
Now go read Narnia D:
Baa baa black sheep have you any booze? No sir, no sir, I'm a....sheep~