Isaak's best known song is "Wicked Game." First released on the 1989 album "Heart Shaped World", an instrumental version of the song was subsequently featured in the 1990 David Lynch film "Wild at Heart". Lee Chesnut, an Atlanta radio station music director who was obsessed with Lynch films, played the vocal version and it became the station's most-requested song. Chesnut spread the word to other radio stations and the single became a national Top 10 hit in February 1991. It also reached No. 10 in the UK Singles Chart. The music video for the song was directed by Herb Ritts and was an MTV and VH1 hit; shot in black and white, it featured Isaak and supermodel Helena Christensen in a sensual encounter on the beach, caressing each other and whispering in each other's ears. Another less-seen version of "Wicked Game" is directed by David Lynch and comprises scenes from the film "Wild at Heart". "Wicked Game" featured as the backing music in the 2001 TV advertisement for the Jaguar X-Type in the UK. In 1995 Isaak split with longtime guitarist James Calvin Wilsey. That year's "Forever Blue" album and the accompanying tour featured Hershel Yatovitz on guitar.