STFU
I remember watching a video by Ryan Higa thinking it meant "stop tickling furry unicorns", it wasn't until I learned what it actually meant years later that I got pretty damn disappointed.
VOD is a close second though. I hate how you could take something that refers to something so general (videos on demand), and over time starr using it to exclusively refer to past Twitch streams. I know that this is what Twitch calls them, and it's technically not wrong to call them that, but it still doesn't make sense when that's all that VOD means nowadays. I miss the days of being jealous at the Americans for having cable.