The DVD audio commentary is one the great inventions of man, next to dark chocolate and the garbage disposal. Great ones I've come across are Sidney Lumet's for The Verdict (because of his professionalism, insight, and utter humanity) and Roger Ebert's for Citizen Kane (because the man is a sponge of information).
But the best is Ken Loring's commentary on the Coen brothers' 1984 debut 'Blood Simple,' a pulpy, hard-boiled noir. The DVD cover touts Loring as a critic and film restorer for Forever Young Films, and it all sounds properly boring. But Loring isn't real. The Coens wrote their own script for the audio commentary, and Christopher Guest regular Jim Piddock delivers it as Loring in his clipped British accent (you may recall Piddock as the "mayor" of Crabbetown in 'A Mighty Wind' or the announcer opposite Fred Willard in 'Best in Show'). 'Blood Simple' is a kick-ass movie to begin with, but the commentary is an added bit of genius, a work of art in itself. In fact, word for word, it might be the Coens' best script ever. Certainly, it's their funniest.
Trust me. Get your hands on the DVD. It's a tour de farce.