A chocolate martini can be made with either Godiva Liqueur or Creme de Cacao.
If you order a chocolate martini in a bar and you do not specify either
liqueur you will get the chocolate martini made with Creme de Cacao, which is
a creme of cocoa. The reason Godiva is more expensive. The difference,
chocolate is sweeter and more syrupy. I would try both, but I preffer the
Creme de Cacao.