For MY money, Robert Ludlum wrote the best Spy novels in print during the Cold War. Unfortunately for him, as the Cold War thawed out, so did his genius for story-telling. You could see it coming a mile away. 'Course he is without a doubt the greatest novelist of all-time who continued to produce book-after-book AFTER his death (although I may be mistaken...). My older brother introduced me to the world of Ludlum with The Bourne Identity, which still ranks as one of the most all-out creative novels of all time (IMO).
One very important thing to remember as you begin the vast majority of Ludlum's novels is that due to the end of the Cold War, a large number of those books are quite out-dated. However, if you can still remember life with the great Soviet Union as our enemy, well you will have PLENTY to keep you entertained.
The Bourne Trilogy, and the subsequent series of films with Matt Damon can be compared, but are almost entirely different aside from the title character and the title of the novels. Other than that, as the series progressed in film, the storylines veered further and further away from the actual books. The Bourne Ultimatum, while in my view was the best of the 3 films, it was my least favorite of the novels.
The Bourne Identity is just a slam-bang great story all around. A man is fished out of the Mediterranean Sea barely alive. A drunken doctor saves his life but recognizes a few things that send up some red flags. He has evidence of Plastic Surgery...and has a small vial of microfilm implanted just underneath his skin near his hip. When he comes to, he has absolutely zero recollection of anything--including who he is. As his health slowly improves, he decides that if he is to figure out anything about his life, he needs to visit the Swiss Bank that has a corrosponding number on the microfilm found by the doctor. While eating at a very public restaurant, a man see's Jason and shockingly recounts that he was certain that he had killed him and before Jason even can understand what has happened, he is in the middle of an amazing fight where he shows astonishing talent for defending himself. He discovers quite by accident that he is proficient in virtually all weapons and before long, as he begins to unravel piece by piece his past, it begins to look like he is a famous hired assassin...and yet he believes inside that he could not be the person that he is discovering that he apparently was at one time. This is where Ludlum's storytelling genius goes into full gear. There was almost nothing I didn't like about The Bourne Identity. Great story, told very well.
As good as The Bourne Identity was, the sequel I felt was even better. The Bourne Supremacy takes up not too long after Identity where the fabled but fictional name of Jason Bourne surfaces in Southeast Asia when a high ranking Chinese Leader is assassinated--supposedly by none other than Jason Bourne. The REAL Jason, whose name is David Webb discovers that he must assume the Bourne Identity once again not only to stop someone from creating havoc in Bournes name, but to also find those responsible for kidnapping his woman. Non-Stop action from beginning to end with an incredible storyline that never ceases to impress and captivate is my best praise. I LOVED this sequel and personally believe it to be my favorite Ludlum novel to date.
The Bourne Ultimatum just wasn't as all-out thrilling as the other two novels...but you have to remember that Ludlum at his worst was still head and shoulders above almost all the other spy novelists at their best. Carlos the Jackal, the main reason for why David Webb originally assumed the Bourne Identity is now after Jason. He has a score to settle and he has done his homework. Digging everywhere to discover who Jason Bourne really is and what he does and more importantly, how to eliminate him for good. The story (as does virtually all Ludlum tales) takes us on a whirlwind tour of planet earth and wraps up in Russia in an authentically built American Town used by the KGB to train operatives before inserting them undercover into the all-American lifestyle. The story fizzles a bit at the end. For me the beginning of the novel set up a much bigger confrontation between Carlos and Bourne, but that payoff never really materialized. But still, a wonderfully fantastic trip back into the world of Jason Bourne and worth every penny.
All in all, still three of the best spy stories ever written, IMO.