Most brands of chocolate sauce that I've found contain HFCS. I got this recipe for a homemade version about a month ago from a member of the disboards. (Thanks, Michelle!) I just got a chance to try it for myself. I made DD3 a glass of "chocolate cow" using this syrup, and it tasted very good. DD loved it.
"Better than Hershey's" Chocolate Syrup
1 cup sugar
1/2 cup cocoa
1/2 teaspoon salt
3/4 cup water
1/2 teaspoon vanilla
Mix sugar, cocoa, salt, and water in a large saucepan. Heat until boiling, stirring constanly until everything dissolves. Remove from heat, and add vanilla.