Sokka interrupting Lao and Aang's discussion of bender and nonbender hostilities because he needs Aang to help him convince himself to buy a new helmet. Aang plays right along.
Aang: Sokka, that's the best helmet I've ever seen you wear. You look like you could take on a herd of rampaging saber-tooth moose lions. Sokka: So I should buy it, right? Aang: Sokka, I think you have to.
Toph's detective work consists of lounging on the beach, letting an Earthbender who blew up her dad's fail at Metalbending, and playing her like she's done it for years.