I don't know... Separated at Birth has the US as a hegemon that spans the entire North American continent, with none of the disadvantages of being the RU tying them down. They also have the egalitarian approach that your TL's US has, even if it isn't as perfect... It also has the advantage of being from a world where the rules of war evolved much differently, take their approach to chemical warfare for instance.
Don't get me wrong though, if anyone in that list could beat Separateverse USA, it would be AMPU USA.