The Manga
Eroica Yori Ai wo Komete was first published in Princess Comics in 1976 and is ongoing to this day. It's written and illustrated by Yasuko Aoike, and has recently been licensed by CMX, the new manga division of DC Comics. It's now available in English and is coming out monthly by volume.
Summary
An action-packed espionage series about the exploits of Lord Dorian Red Gloria, an aristocratic British art thief known as "Eroica", and his nemesis, the German NATO intelligence officer Major Klaus Heinz von dem Eberbach. They are total opposites in temperament and physical appearance but their paths cross through accident, reluctant collaboration and manipulation as the unashamedly gay Eroica pursues his beloved Major all over Europe, the Middle East & the US.
This series is so slapstick (and so very Cold War era), it'll have you in stitches from the get-go. Think of all the impossible things that have happened in every bad 60's spy movie you can name, and combine it with some Starsky and Hutch and just a dash of The Italian Job, and you'll have something that vaguely resembles Eroica, but that isn't quite as flaming. Yeah, it's that weird. You'll either love it or hate it, so if you haven't read it yet, pick up volume one sometime and see what you think!