21 Jump Street Gallery
Peter DeLuise as Doug Penhall
Peter DeLuise is fortunately a prolific episode commenter and he's also the only one doing them on the 21 Jump Street DVDs. He's hilarious and his comments alone are worth the price of the DVDs. It's amazing what he remembers 17 years after the filming.
For 21 Jump Street, he did:
Season 1: 1x07, "Gotta Finish the Riff"
Season 2: 2x09, "You ought to be in Prison"
Season 5: 5x14, "Film at Eleven" - also directed the episode
Season 5: 5x10, "Number One with a Bullet" - also directed the episode
Season 4, episode 15, "Back From the Future" was his directorial debut of a TV episode - Strangely enough, it's not one of the ones he comments.
4x15 has bloopers during part of the end credits.