Fleetwood Mac, 1977. ~40 million copies. Five members, every romantic combination broken, recorded into the album.
From Wikipedia
Rumours is the eleventh studio album by the British and American rock band Fleetwood Mac, released on 4 February 1977, by Warner Bros. Records. Largely recorded in California in 1976, it was produced by the band with Ken Caillat and Richard Dashut. The recording sessions took place as the band members dealt with breakups with one another and struggled with heavy drug use, both of which shaped the album's direction and lyrics.