Bowling is apparently a huge deal in Bowling King. No, seriously. Professional bowlers are all either incredibly badass or Bishōnen prettyboys. Oh, and then there's how main character Shautieh Ley's ultimate goal seems to involve taking over the world with bowling somehow; while this isn't explicitly stated, chapter opening pages tend to feature things like a Rushmore Refacement where all of the faces are Shautieh (and similar ones with the Sphinx, etc.) and Shautieh disrupting other sports events.
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. This a Lampshade Hanging on how writers in comics loved to remove problems by having them turn out to take place in alternate universes.
"You don't understand man." "He TOUCHED my dice!"note Ask any hardcore gamer in Real Life. Touching someone else's dice/mini/whatever without permission can be considered a breach of etiquette, and with some players, is indeed Serious Business.
In one Calvin And Hobbes strip, Calvin throws an enormous hissy fit after losing a game of checkers to Hobbes. When Hobbes points out that it's just a game, Calvin cheerfully replies: "I know! You should see how I act when I lose in real life!"
Chewing gum is Serious Business in the Calvin And Hobbes universe. Calvin is an enthusiastic reader of a magazine called "Chewing" which is dedicated to it, and informs an incredulous Hobbes that as many as twelve such publications exist.
This comic was based on one of Scott Adams' coworkers, who actually said "I will fight you to the end of the earth!" To him, it was serious business.
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-activities, heroic and villainous alike. So, what is left for them to be enemies over? Why, the apple tree that looms over both their properties, 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.
The people of a Hannoverian village who want to celebrate the birthday of their ex-king (Hannover was conquered by Prussia in 1866; some people nursed a grudge because of this, and pro-Prussian Wilhelm Busch wrote this story as a Take That).
Pinkie Pie: Luckily, I always travel with an "I'm sorry" cake! I also have "I am sorry" goodie bags! Twilight Sparkle: Uh, Pinkie, I don't think we have time for cake... we are only an hour away from the Changeling kingdom... Pinkie Pie:EAT... THE... CAKE.
When Wonder Woman was stuck working at Taco Whiz, she took the job very seriously. Then again, she takes everything seriously, except Batman's brooding.
According to the Batman: The Animated Series "Mad Love" comic, The Joker takes comedy very seriously. Only he gets to tell jokes during his crimes; he throws a tantrum if anyone else makes a crack. And if people don't understand one of his gags and he has to tell them why it is funny, that takes all the fun out of it - even if it involves killing Batman.
Joker[angrily, to Harley Quinn]: My jokes are elegant in their simplicity. You see them, you get them, you laugh - end of joke! You should have remembered when I told you that a long time ago; it's one of the few real truths of comedy!...You're always taking shots from folks who just don't get the joke![strikes Harley repeatedly with a large fish, sending her crashing through a high window and down to the street far below, nearly killing her]