Chocolate is a human delicacy, of which the most important ingredient is cacao, which is derived from the cacao tree. Its main application is in sweets and different kinds of candy bars, cookies and various confectionery.
On numerous occasions, off-world teams have used candy-bars or regular chocolate bars to smooth first contact situations.
When Major John Sheppard's team arrived on M7G-677, Lt. Aiden Ford introduced the local children to chocolate. Later Dr. Rodney McKay used their new-found love for this substance to bribe Cleo and Casta. Just before leaving, the team gave a bag of chocolate bars to Keras as a birthday present which he then graciously shared with the others. (SGA: "Childhood's End")
On the Destiny, the crew lamented the lack of chocolate. Dr. Inman said that it would require 12,000 chemicals to replicate the taste of chocolate, and no scientist is able to replicate the taste of chocolate properly. (Kino: "Variety")