DeviantArt user Prathik designed some awesome hoodies with an Avatar: The Last Airbender and Legend of Korra theme. They look amazingly similar to what the characters wear in the show.
Prathik pretty much created hooded versions of the character's costumes and identities including Aang, Katara, Korra, and Zuko. Spirits, Vaatu and Raava, make for some cool designs.
Even Amon's red dot is included for his hoodie.
The hoodies also included Lin Beifong with her metal armor, the uniform of the fire ferrets, Kuvira, and even hoodies for the air nomad in you.
Prathik also designed hoodies inspired by the comics of Marvel and DC.
I wish these hoodies are real. I want to buy one. Prathik, get in the designing business my friend!