I hate France so much, they're just completely unstoppable. An alliance of Great Britain, Austria, Poland and Lithuania can only fight them to a stand still at best.
I second that, in my Muscovy/Russia game they're the ones with the largest army, force limits, manpower and so far can take Austria-Hungary and the entire HRE plus Spain and Portugal alone. (I mean, they have a few vassals but I doubt they actually do anything...)