Invented in Budapest in 1974 — and still one of the best-selling toys on the planet, over five decades later.
Rubik's Cube (1974) was a genuine nationwide craze decades before "going viral" was a phrase — and it's still made and sold today. This is a genuine pre-internet product — a real, nationwide sales phenomenon decades before social media existed, spread by nothing but word of mouth, in-store demonstration, and traditional advertising. Many of these are still in production today, largely unchanged.
Ernő Rubik built the first cube as a personal exercise in 3D geometry, not intending to sell it at all. It reached the US in 1980 and sold over 100 million units in its first three years alone.
It never really went away, and TikTok's #CubeChallenge speedcubing videos gave it another real resurgence starting in 2022 — proving the puzzle format still works on a completely different medium than the one it launched in.