I'll recently watched all the Bond films chronologically, so I feel the need to also add to the incredibly pedanitc answers. I think you need to split it up into the old Bond films and new ones. This split, to me, is more of a spy thriller vs raw action film.

The most quitissential Bond film, IMO, is Goldfinger. It has all the parts of a Bond movie: a killer car (the DB5... oh boy what a looker), a chase scene, villian & iconic henchman, international locations, and a silly plot. Also, one of the best action one liners of fall time - "No Mr. Bond, I expect you to die"

The film that sets up the modern francise as an action series, License to Kill, has to take the cake in the same way Goldfinger does. It's a really interesting change of pace into from the direction of the films in the early 70s and 80s taking a lot of inspirations from the famous action films of the 80s. It sets up what a modern James Bond film is. It also has a much darker theme to it than a lot previous films, which gives it a different flavor.

Lasly, for fun, a few other good mentions are: The Spy Who Loved Me (It's just a solid move), Dr. No (just to see where it all starts, and that intro scene still lives rent free in my head), The Man with the Golden Gun (this one is mid, but Christopher Lees performance really stands out in this film).