Kronos Quartet Recommendations?


I've read great things about the Kronos Quartet and I'm interested in picking up one or two disks. Anyone familiar with the Kronos Quartet have suggestions?
tvad
They did a recording on Reference Recordings called In Formation. An audio buddy of mine has it on 45 rpm vinyl and, boy, is it stunning.
Philip Glass String Quartets (Nonesuch 79356). Includes quartets 2, 3, 4, and 5. Quartet No 3 has the Mishima film music, mentioned earlier, though it is not the soundtrack.
Thanks everyone! What a great response to my question. I've ordered "Pieces of Africa" and "Piano and String Quartet" for starters. I recall "Requiem for a Dream" as an amazing film with extremely effective music, so that may be on the short list.
They have kind of a best of called Released. Since their albums tend to be themed in sound, it might be a good starting point. (ie, if you like the sound of a song, you'll probably like the album it came on.)

Their new Mexican album is cool.

(I thought Kids was far more disturbing thean RfaD, but what do I knw?)
Also on Nonesuch there's Kronos plays Alphred Schnittke with nice book that you will find very interesting to read especially when listening to CD itself.