Noteworthy cultural phenomena?

A cultural phenomenon is more than something popular for a week. It catches on across a community and starts shaping how people talk, dress, make things, or see themselves. Sometimes its influence lasts; sometimes the brief burst of attention is the story.

Examples include Beatlemania in the 1960s, the spread of hip-hop from local scenes into global music and fashion, Pokémon’s cross-media reach, and global K-pop fandom. Internet meme culture is another kind of phenomenon: jokes and images travel quickly, but they can also become shared references that signal belonging to a particular online group.

What makes these worth discussing is not popularity alone, but the way they cross into everyday life—changing tastes, creating communities, or influencing later work. Which cultural phenomenon do you think has had the biggest impact?