Two Words, James. Bond.
Yeah I've watched these all before, when I was like 12, but now as an adult I've been revisiting them, seeing how they hold up to my now higher standards.
The Short Answer? They don't. The Long Answer is that you gotta understand the time period in which the movie you're watching was made, because for Bond films that has a significant impact on every single character interaction you'll see.
However the stunts are always fun, the villains are always entertaining, and the songs are usually good. My advice would be to avoid the Roger Moore ones if you're looking for a more serious spy-thriller. Sir Roger Moore is a fine actor, but even he decided he was getting too old for the role and left. Plus I'd bet money that every 70's entry he starred in was made with a notable amount of cocaine present in the writers room.
