Sorry if this one has already been covered.
I'm talking about scenes where a person or persons (almost always adult men; rarely women or children) are wearing a nice, clean, fancy, expensive suit and a tie. And because of the violence that they go through, their suit gets horribly mangled. It could be covered in blood, dirt, or it could be torn. Regardless, the damage of their clothes is contrasted with how nice those clothes are. Usually, people working white-collar jobs won't have to go through violence, so this is done for humorous value or ironic effect. To add to this, they're often doing things you wouldn't expect people wearing those clothes to be doing, like dropping Cluster F-bombs, committing very serious crimes, or performing sexual acts. Bonus points if the person dies in the suit. I'm sure there are tons of examples, but I can't think of many right now, so here goes. Apologies if what I'm saying is too general to make a trope out of.
- Pulp Fiction: Probably the most obvious example. Jules and Vincent are all covered in blood after Vincent's mistake.
- Reservoir Dogs: Basically everyone. Lots of people get a ton of blood on their suits.
- Kill Bill: Quentin Tarantino really loves this trope, huh? The Crazy 88 fight in the first film has a ton of this.
- Pineapple Express: Mostly just Saul, but he's a process server and at the end of the film, his suit is all in a mess and he has to be taken to the hospital.
- Final Fantasy VII: A certain character is impaled by the game's villain while wearing a suit.
- Yu-Gi-Oh! (animated series): I think the character Pegasus was describing that when the illustrators at his company were working on the design for the Egyptian God Cards, they mysteriously disappeared or were killed.