Pac-Man, Space Invaders, Frogger. The video games of the 1980s were played in arcades, pizza parlors and bars--and all you needed was a quarter to join in the fun.
From the time Space Invaders appeared in 1978, until game consoles took over in the mid-1990s, arcades were the center of the video gaming world. The classics that were produced in the "golden age of arcade games" are still very much alive today. You can play the games for free on many Internet sites and new and new versions, like the Xbox 360 Pac-Man Championship Edition are still being produced. Many original arcade machines are available for purchase.
Note, some of the games listed were introduced in the late '70s but were still very popular throughout the next decade.