The Bourne Series
I just read the first two books in the past couple of days and I was really surprised how different they are than the movies. Totally different storylines. But I liked the Bourne Identity better than Supremacy. Supremacy seemed not as shocking and didn't have as many twists and turns.
The only thing that annoys me about Ludlum's writing is that he always puts things in italics when people are talking. If used sparingly, this is a great device, but he uses it in just about every conversation and it gets old.