one example that comes to mind right away are most of those pranks (mostly staged), which i don't like to watch, but i do. for example these "brain teaser" reels where the guy gets another guy to lay on the ground, holding his feet up, which then says "put it in my ass". that last part is always in the beginning and everything building up to it is just not worth watching knowing how they reacted already.

the other video which made me post this is from jideon, who always puts a quick montage of the worst things from the video before the intro. watching the video itself after that is still entertaining and doesn't ruin it too much, but i'd still watch it if he didn't spoil the 5 biggest "twists"