Gong Hyo Jin is definitely an acting legend.

A popular post on internet community forums noted that the popular actress has never starred in an unsuccessful drama 20 years after her debut in 1999. 

The char above notes that all the dramas that Gong Hyo Jin starred in never reached lower than 12.9%. Although many actors are successful overall, there are bound to be some projects here and there that don't do as well. Gong Hyo Jin's impressive track record shows her popularity in Korea.