I was hoping that Conan O'Brian would be on more than one of the commentary tracks for the Simpsons Season 4, but I guess not. Still, it's a must-buy.
Here's a list of the commentary tracks.
EP 1 - Matt Groening, Al Jean, Mark Kirkland, David Silverman
EP 2 - Matt Groening, Al Jean, Mike Reiss, Jeff Martin, Jon Lovitz, Hank Azaria
EP 3 - Matt Groening, Al Jean, George Meyer, Jim Reardon,
EP 4 - Matt Groening, Al Jean, Mark Kirkland, Jeff Martin
EP 5 - Matt Groening, Al Jean, Jay Kogen, Wallace Wolodarsky, Jon Vitti
EP 6 - Matt Groening, Al Jean Mike Reiss, Rich Moore
EP 7 - Matt Groening, Al Jean, Bill Oaklet, Josh Weinstein, Jeff Lynch, Jim Reardon
EP 8 - Matt Groening, Al Jean, Mike Reiss, Conan O'Brien, David Silverman
EP 9 - Matt Groening, Al Jean, Jon Vitti, Jim Reardon
EP 10 - Matt Groening, Al Jean, Jeff Martin, Mark Kirkland
EP 11 - Matt Groening, Al Jean, Mike Reiss, Michael Carrington, David Silverman
EP 12 - Matt Groening, Al Jean, Mike Reiss, Conan O'Brien, Rich Moore, David Silverman
EP 13 - Matt Groening, Al Jean, Mike Reiss, David M. Stern, Jim Reardon
EP 14 - Matt Groening, Al Jean, Mike Reiss, Jon Vitti, Jeff Lynch
EP 15 - Matt Groening, Al Jean, Frank Mula, Wes Archier, David Silverman
EP 16 - Matt Groening, Al Jean, Mike Reiss, David M. Stern, Jim Reardon
EP 17 - Matt Groening, Al Jean, Jay Kogan, Wallace Wolodarsky, Mark Kirkland
EP 18 - Matt Groening, Al Jean, Mike Reiss, Jon Vitti, Jeff Lynch
EP 19 - Matt Groening, Al Jean, Mike Reiss, Adam I. Lapidus, Rich Moore
EP 20 - Matt Groening, Al Jean, Mike Reiss, Jeff Lynch, David Silverman
EP 21 - Matt Groening, Al Jean, Bill Oakley, Josh Weinstein, Jim Reardon, Jeff Lynch
EP 22 - Matt Groening, Al Jean, Mike Reiss, David Silverman