I'll just quote John Dolan's review of The Hunt for Red October.
"Clancy's first and most famous novel is a classic. And I don't mean that in a nice way. The story displays complete ignorance of Russian military culture; the dialogue is unworthy of cartoon characters; the "action" is a far-fetched excuse for long pedantic discourses on weaponry lifted from the pages of Jane's and Aviation Week; and the author is a draftdodging hypocrite rightwinger who somehow elected not to fight in Vietnam and spent the rest of his life becoming enormously rich lecturing fellow cowards on the wonders of modern warfare. In short, it's the perfect book for the American electorate. You go girls! "
I too have read a lot of his books, specially the one made into movies. He was a very intelligent writer. My favorite book and movie based on one of his books is The Hunt for Red October.