These guys have consistently released some of the best American music around for entirely too long. I'm not familiar with all the bands of the collective (I wonder if they even are) but Neutral Milk, OTC, Circulatory System, Apples in Stereo and Of Montreal are some of my faves.
Let us begin a discussion of these fantastic musicians.
And, if you haven't heard any Elephant Six music, go to www.elephant6.com and get some of the free live shows they've posted up there. Olivia Tremor Control and Neutral Milk Hotel both have fantastic recordings up.