On the face of the evidence, Karlheinz Stockhausen's Mantra is that composer's most widely-recorded and -performed piece. There's the Bevan/Mikashoff recording which I reviewed; the Kontarsky version issued through Deutsche Grammophon / Stockhausen Verlag; the Corver/Grotenhuis version (Stockhausen's alleged favorite, which is not in print); a version by Janka and Jurg Wyttenbach; and the Schumacher/Grau version on Wergo, which I now also have and admire quite a lot.
And now we have yet another one, by Xenia Pestova and Pascal Meyer, which substitutes the analog electronics called for in the score with an all-digital, computer-driven setup. They used Max/MSP, the same suite that Merzbow now uses on his Mac for his laptop-based compositions. You can even download the same patches and wiring diagrams they used, if you've got three pairs of hands and want to give the piece a shot yourself.