Microsoft Solitaire on Windows 95

Bundled with Windows since 3.0, Solitaire is quite possibly the most-played video game in history — and it was secretly a tutorial. Microsoft included it to teach a generation of new users how to use a mouse: clicking, dragging, dropping. The green felt, the little card backs, the satisfying snap of a card landing on a foundation pile — and of course the legendary win animation, cards cascading across the screen in endless fountains. Decades of office productivity were quietly sacrificed to this humble card game.