naruto would most definetly win for the simple fact he has controlled the nine tails chakra he also has sage mode
depends, are both characters at their peak? are they at full power? full training? or are they beginners.... or moderately skilled? Need more details.
This appears to be a bit of an impossible question. And, assuming that they are both at full power, they're pretty evenly matched. Naru-nine-tails is gonna grind you into a crater in the earth? Well Aang's gonna do that too.
But forget battle skills at full power. Who'd win in a contest of full power facial-markings is what I'd like to know.