The TV Addict 

Firefly, particularly the commentaries for ‘Serenity’ and ‘War Stories’. They are hilarious, while giving insightful looks into the making of the episodes (including goofs), the backstory of the series and for added fun, there are some snarky comments thrown at Fox. You can really tell that everyone involved loved working on the series. Commentaries for seven of the fourteen episodes are included, all but one with at least two people talking, including several of the actors, Joss Whedon, Tim Minear & Jane Espenson.

Supernatural had commentaries from both leading actors Jared Padalecki & Jensen Ackles and Roswell had commentaries from both leading actress Shiri Appleby and Majandra Delfino. And they both sound happy doing it, they laugh and put there 2 cents. Boy Meets World also had great commentaries by the cast. Rider Strong, Matthew Lawence (And he wasn’t even in that season) etc..

Everwood has big party commentaries that are a lot of fun. As the DVD goes along, more and more people are added to the commentaries and by the last one, it’s like ten people. Tons of jokes, but some great insight and you just get the sense that these people love the show as much as the fans do, and that they all get along and have fun.

Futurama commentaries are also great. Again, it’s just a lot of fun with a whole slew of people. Lots of jokes, occasional insight and people enjoying their own work, but not in an annoying way. Plus they do it for every episode, which is kind of insane, but they find things to talk about or make fun of or whatever. Fun stuff.

Firefly… and Supernatural. The commentary by Kripke was great.

Yeah, I don’t have anything else because most of the time we don’t get the DVD commentaries on our releases. Oh why wasn’t I born in the US?!

I say Freaks and Geeks. Every episode has multiple commentaries and a few have people doing commentary in character. It’s pretty awesome.

I think a great commentary is to come. On the Supernatural Season 2 DVDs they’re having Jensen and Jared do a commentary on their season 2 premiere “In My Time of Dying” with Kim Manners, an executive producer. Jared and Jensens commentaries are fun because they ARE fun plus with a director the fan’ll get a lot of insight. Plus, they are all hilarious.

As for as Supernatural goes, they’ve done 2 commentaries on each dvd set so far and have a lot of behind the scenes stuff to make the fans happy, no matter if they get paid or not from it.

I think “The Office”, “Scrubs”, and “Greys Anatomy” commentaries are my favorites.

Supernatural and Firefly definately. Eric Kripke’s commentary is always insightful and funny and gives us great history on the show. Jared and Jensen’s ommentary on Season 1 DVD’s was funny and you could really sense that their friendship was real. They really seemed to love what they were doing. I agree with Shannon that more great commentaries are to come with Season 2. Kim, Jared, and Jensen should be great and I expect a lot of laughs. Kripke and Singer are commentating on the finale and I’m looking forward to great making of stories.
Firefly’s commentaries are awesome as well. Nathan Fillion is always a joy to listen to and him and Alan Tudyk make up a great combination in ‘War Stories’.

Also felicity, i like the season 2 commentery with all the other actors too

Oh, and Mr. Show commentaries are as scripted as the episdoes themselves — bringing in their #1 obsessive fan to comment on shows along with them (voiced, I think, by David Cross), random characters coming in and out of the room, various co-stars (Poesehn, Silverman, Black) coming in for select eps….this should could still be on and still be oddly hiliarious.

Love, love, love the Arrested season 3 commentary, especially when they ring up the guy who plays George Senior/Oscar (can’t believe I forgot his name) just so all the cast are on the commentary.

Supernatural’s is great as well, you can really tell that Jensen and Jared get along well.

Joss Whedon does great commentaries… my favourite is “Innocence” from Season 2 of Buffy.
Aaron Sorkin and Tommy Schlamme do some interesting ones on The West Wing. They aren’t the greatest but there are a couple times that they’ll point something out or explain a metaphor that you completely didnt get which is kind of cool. ie: did you know that every episode the art department makes a different figurine to stick in the bottom of CJ’s fish bowl as decoration even though we never really see it?
It’s also funny to hear the producers talk about the actors. Both Whedon and Sorkin love their respective Allisons.
Oh and I really like The Office season 2 commentaries
On Six Feet Under though they tend to just talk about why their show is better than everyone else’s which gets kindof annoying.