Clockwise from top left: The Night Manager , A Spy Among Friends , Killing Eve, Slow Horses . Photo-Illustration: Vulture ; Photos: Des Willie/The Ink Factory/AMC, MGM, Jack English/Apple TV+, Nick Briggs/BBC-America/Everett Collection This list was originally published on April 26, 2018. We’re not so covertly republishing it now to mark the premiere of Slow Horses season five. The small-screen British spy genre is packed with some of the most tonally diverse marvels under the sun — pick one