Someone told me Texaco is the best. I think they invented it.
Chevron/Texaco (Havoline) originally developed DEX-COOL for GM. Now, any coolant labeled as such is made the same way and, may in fact be made under license from GM.
I can't imagine why I would want to be brand specific on the Dec Cool I buy. I think I have been buying the Prestone branded stuff that Walmart sells (or whatever they sell at WalMart).