everyones talking about how Aang defeated an entire fleet of war ships from the FN in ''The Siege of the North'', but i really have to disagree. he didnt do that on his own. He got most of the power from the Ocean Spirit, just look the episode again and ull see that the eyes of the fish are glowing just before Aang takes control of the water. Also the Spirit is swimming circles around him, and just before Aang sinks into the water, the Spirit makes eyecontact with him. I think its smart of Aang that he's not going to fast with defeating the FN and especially the Fire Lord, because at the moment he wont be able to without the help of a spirit.
wow, thats a nice new theory... maybe Aang will need the help of the spirits to re-create balance on his world. ah well... thats an off-topic i guess