u/Mr_Muda_Himself_V3

Bowser vs Eggman

Mario vs Sonic

Kenjaku vs Makima

Megatron vs Vilgax

King Piggy vs Dr.Zomboss

The Smiling Friends vs The Park

Aang vs Steven

Team Fortress vs The Z Team

Homer vs Peter

50 Saiyans vs 50 Viltramites

Eve’s Pregnancy (Invincible: The Viltrumite War) Eve is one strongest and most versatile heroes earth has to offer and her powers of matter manipulation could easily turn the tide in the coalition’s favor (and that’s not even getting into her unbounded state) so to make sure the war has some actual stakes, the had mark get her pregnant which resulted in her losing her powers forcing her to sit on the sidelines for the entire arc.

Sending Hulk to space (Marvel: Civil War) one of the main issues of the writers of the Civil War event faced when coming up with it was the fact there’s a shit tone of Uber powerful heroes whose which ever side they’d join would just automatically win, namely Thor and Hulk, luckily for Thor he’s been dead for a while due to a previous event in his own comic, but what about Hulk you ask? Well apparently before the whole civil war thing even started, the 5 smartest heroes on earth (Iron Man, Doctor Strange, Mr.Fantastic, Black Bolt, and Professor X) all decided "Hey, you know one of our best friends who has helped us through multiple crises and has been shown to be able to be far more than just a mindless monster? Let’s drug him and send him into space because we’ve arbitrarily decided he’s too dangerous to be around NOW."

Goku’s Heartvirus (Dragon Ball: The Future Timeline) The point of Android/Cell Arc was the fact as soon as Goku died everything went to shit, so going back in time and saving Goku before he dies is our heroes only option, and yeah by multiple creator statements, games what if scenarios and characters in story themselves if Future Goku Survived he would’ve put belt to the androids, avoiding the bad future we have now.