Book 1 Chapter 5: The King of Omashu Aang, Katara, and Sokka are brought before a crazy old king, who seems to enjoy messing with their heads. (This is my least favorite episode so far. :/ Unfortunately, it's also very important for the second season. ...But it introduces Cabbage Man, yay!)
Book 1 Chapter 6: Imprisoned Katara attempts to inspire the oppressed people of an Earth Kingdom city, occupied by the Fire Nation. (This episode and the one before it are the first times you really get to see Earthbending in action. Pretty cool.)
Comment if you download plz~! Also, you can still download the other eps if you haven't already: One and Two, Three and Four.
EDIT: Omg omg, the First Season Set looks so gorgeous. o__o I feel conflicted now; continue buying DVD releases, or wait until September?? Maybe if I sell the DVDs on Ebay and save the money....gah, but I like the DVD artwork too! SO CONFLICTED.