Serious Business/Comic Books

DC Comics had a Golden Age hero called Manhunter, then bought another Golden Age hero called Manhunter. In a Retcon, the two men had an argument over who got to keep the name, and they settled it by having one of them go to another universe.
- That's a Lampshade Hanging on how writers in comics loved to remove problems by having them turn out to take place in alternate universes.
Knights of the Dinner Table has roleplaying games as serious business.
- "You don't understand man." "He TOUCHED my dice!"
Bookhunter takes place in an alternate-universe 1970s where books and libraries are so important that an entire branch of the police is devoted to investigating library-related crime.

Agent Bay: In many respects the American Library has become the most basic First Amendment institution. We are guards, yet we guard no less than the sum of human knowledge. We are the library police.

In Welcome to Tranquility Captain Cobra and Mongoose Man are not just enemies, but "enemies to the death." Unfortunately, their advancing years are actually bringing them pretty close to that goal line and they have both retired from super-activites, heroic and villainous alike. So, what is left for them to be enemies over? Why, the apple tree that looms over both their properties, of course, and who has proper ownership over the apples that fall down on either side of their fence. Just ask Sheriff Lindo, apples are serious business.
Beef is Serious Business in the Crapsack World of Give Me Liberty. Fast-food restaurants wage wars for farmland, people commit suicide for hamburgers, and there's even a 94th Amendment outlawing red meat.
One Cthulhu Tales comic had an unnamed "Maine Cheetahs" baseball fan (according to Google, no such team exists) for whom baseball was such serious business, he went so far as to invoke Cthulhu in order to win them their first World Series in seventy years. It doesn't appear to end well for anyone concerned.