A huge part of the Pirates World Series win in 1979, he got a second ring in 1989 with Oakland. An MVP in 1978, likely the best player in baseball from 1977-1979. He also came in second in MVP voting in 1985 and third twice, as well as getting votes 5 other times. 7 time All-Star, 3 time Gold Glove, led the league in batting twice, doubles twice and RBI once. Hit 339 homers, drove in 1493 and had a .290/.339/.471 batting line in a 19 year career. He finished his career with the Jays. His full numbers are here.
He also had a bit of a cocaine problem. Course, throw a dart at a list of top MLB players from the late 70s and you'd likely hit one that used coke.