I really like the LOTR commentaries - both official and WAYDM.

Joss Whedon's commentary for the Avengers is pretty good. That man is frighteningly brilliant.

I've been public about it, but the Boogie Nights commentary is great.  It's so casual, people are cooking, there's a baby somewhere, but in the middle of it all people are having a great conversation about the film.  It fit for the ensemble nature of the film.  Just a lot of fun.

I have an allergic eration to hearing my own voice, but in terms of WAYDM commentaries I've been on, I think the ones I can stand to listen to are Twilight, LOTR, Alien, and The Prestige.  Of commentaries I wasn't on but I really dug, Raiders was great.  Abyss was the very best of the man called Trey.  There's a million I'm leaving out, but off the top of my head those are good ones.

The Lost in Space commentary is very fun, as I believe the writer and director go into detail what the hell went wrong, what the original idea was and what the sequel was going to be like. Production was a clusterfuck, and they admit to it.

You'll get it, soon. For most people, the shoe drops by the 15 minute mark. Can't really say too much more without spoiling it though.

edit: and the first few minutes is obviously all the "hello, how was your week?" stuff. film review starts about 7 minutes in

Disclaimer: if you dislike the tone of a post I make, re-read it in a North/East London accent until it sounds sufficiently playful