If you're buying the FAMILY GUY DVD set for the commentary, forget it.
Jim Wynorski's commentary for the THE BARE WENCH PROJECT 2 was more enlightening. And no, that's not a compliment.
We have five people sitting in the commentary chair to give useful input, and no one says anything for more than 30 seconds at a stretch. In fact, no one says anything useful related to the episode in question, ever.
I like the show, but goddamn. If you just wanted to buy for the special features, save yourself the trouble and tape Adult Swim.
Worthless.