Corn syrup isn't just for soda. A derivative of corn starch, this mixture of corn syrup, high-fructose corn syrup, salt and vanilla is most commonly used in my home is for making caramels and Molasses Softies. Corn syrup hasn't been around much since before the 1950s. Caramels made before then used different varieties of sugar, which is more prone to crystallization than corn syrup. If you have ever had a seemingly perfect batch of caramel crystallize hours after making it, you can appreciate the benefits of corn syrup.
Corn syrup is pretty straightforward ingredient. I can't really recommend one brand over another. Karo seems to be the most prevalent brand where I live. Corn syrup comes in light and dark varieties, with light being the most commonly used. Dark corn syrup usually contains some caramel coloring and molasses. You can interchange dark and light, but be aware that the dark corn syrup has a much stronger flavor while light is far more neutral.
