I've been wanting to write this for the longest. Without going into details, here's my ending (remember this is just what I think):
-Aang deafeats the Fire Lord
- Iroh is killed by the Fire Lord when he self-sacrifices himself for the lives of Aang & Zuko
-Zuko deafeats Azula & she meets her demise by her own hands while trying to kill her brother
-Zuko is given the thrown (being the only family left), but declines it (the Fire Nation will have no more Fire Lords) and decides to aid the victims of the war
-All the nations come together as one
-And those 2 guys that were suppose to get Toph are still stuck
As for Zuko's mother & the fate of the Suki, I haven't got a clue. Anyway, thats mine, now lets here yours!