The Bourne Trilogy of spy thrillers rank among my favorite films. It is probably their influence which makes Knight and Day, a romantic comedy/spy thriller hybrid, so amazing.
Knight and Day has all of the elements of an excellent spy thriller. There's the dashing secret agent, resourceful and clever, fighting against larger forces by himself. There are car chases, massive gun fights, intrigue, betrayals, and double crosses. Then, just to totally mess with the formula, instead of throwing in a femme fatale they inject a fairly normal woman who is totally unprepared for anything that is about to happen to her in the movie.
The twist on the formula not only works, it's simultaneously hilarious and engaging. While almost everything in the film can be mapped to various cliches from both genres, the combination of the two reminds me of such films as To Catch a Thief or How to Steal a Million. Knight and Day catches that classic up to the present day beautifully and seamlessly.
I highly recommend this film. It's only PG-13, it's over the top, and it's absolutely enjoyable.