An Audi car commercial involved a party of vampires being incinerated by the bright headlights of the car being advertised. Aside from a few behind cover coming up (possibly because they didn't connect the silence with being something deadly and wanted to see what was happening), the vampire driving the car gets out...and walks into the path of the headlights. He is incinerated.
The "Don't Text While Driving" PSAs invoke this, showing testimonials of families who have lost loved ones who were paying more attention to their texting than the road.
One Fruit Gushers ad campaign depicts people licking various semi-liquid material without any sort of abandon (such as squid ink, for example) and reacting in shock when, no, it doesn't taste like the fruity filling that Fruit Gushers are known for. It's very much Played for Laughs, as most of the time the person's peers look on with looks of bewilderment and/or disgust as they lick the foreign object.
One early advertising campaign for GEICO featured something like this; each animated short had a curious man doing something really dumb (like walking up to a cannon and then pressing a button next to it, causing the cannon to fire in his face), at which point the voiceover announcer would say, "We all do dumb things. Paying too much for car insurance doesn't have to be one of them."
Another GEICO example: "Horror Movie". Even the Killer does an eye roll and has a look on his face that simply says "Yeah, these kids are so stupid they need to die".
Teen #1: Let's hide in the attic!
Teen #2: No, in the basement!
Teen #3: Why can't we just get in the running car?!
Teen #4: Are you crazy?! Let's hide behind the chainsaws!
Teen #2: HEAD FOR THE CEMETARY!!!
The people from the Jack Links Beef Jerky "Messin' With Sasquatch" commercials. Seriously, it's not worth it for just a few laughs!
An Australian Metro safety ad presents a three-minute song: "Dumb Ways to Die". It went viral.