1. I got a little glimpse at "Sozin's Comet" and i feel kind of sorry for Azula, i think we started to see a more gentler side of her in "The Beach".
2. I was just thinking about the episode "The Runaway" and looking through it's screencaps. And i find the scene where Sokka and Aang are trying to reconcile Katara and Toph, a bit ironic somehow, since, in a few more scenes, this feud nearly cost Aang his life.
3. The same goes for "The Guru" in irony. Pathik told Aang to let Katara go and not to leave before unlocking his final chakra. And because Aang didn't let Katara go and left before his training was complete, he nearly lost his life.