Red Dead Redemption. That's right -- this film was created using in-game assets. And it's not just any old basement machinima -- it's been directed by John Hillcoat (The Road) and, according to Rockstar's description, "reimagines" protagonist John Marston's, uh, redemption, as he pursues that prickly Bill Williamson.
Sounds interesting enough -- just so long as it doesn't interrupt MADtv. That's still on, right?