Jerry Lewis, No. 97, Nov.-Dec. 1966
I forget when I spotted my first copy of Jerry Lewis's DC Comics book, but imagine my astonishment to learn that it ran from 1958 to 1972. It was actually Dean Martin and Jerry Lewis in four-colour pulp form before '58, but that ended with the split, and it was decided Lewis was the better option for an ongoing series (although a Dino comic, with his continuing Rat Pack adventures would have been way cooler).
DC Comics also had a Bob Hope comic book, but I have no idea if he ever clashed with the Joker or not (although he could be the Riddler's dad, you can tell by the nose).
I actually own the issue pictured above...Lewis and his young sidekick Renfrew watch an episode of the camp '60s version of Batman, and decide to become masked avengers Ratman and Rotten, the Boy Blunder. Eventually they tangle with the Dark Knight himself, and a bunch of his arch foes. It's not much, but it beats all those other issues that find it endlessly hilarious to have Lewis tangle with a large gorilla. I have no idea if that's supposed to be a dig at Martin or not.