u/ARAMF

Aragorn: Viggo Mortensen breaking his toe for real during this scene in LOTR where he kicks a helmet on the ground.

Spider-Man: While in Peter's body Doc Ock punched Scorpion's jaw off during a fight which was seem as an example of how much Spider-Man holds back during fights. This fact is now frequently brought-up a lot in vs. debates featuring Spider-Man and even in non-strenght related discussions.

Plastic Man: Similarly to Spider-Man, Plastic Man is another character who is frequently brough-up in "actually, they're way stronger than they seem" discussions, but due to the fact that he is not as well known as Spider-Man this subject seems to dominate discussions related to the character way more than they do for Peter. One frequent piece of trivia that is used to showcase Patrick's strenght is that unlike all other Justice League member, Batman has no contingency plans in case Patrick turns evil, he just hopes that he doesn't.