My all-time favorite American TV spy show is by far "I Spy." It had great locations, believable espionage stories, and--most important of all--the chemistry and wit of stars Bill Cosby and the late Robert Culp. And one minor bonus: Cosby and Culp wore really cool Rolex Pepsi GMTs.
The enthusiasts over at watchsrolex.com wrote a nice piece in memory of Robert Culp, who passed away in 2010. You can read it here.