Apollo 13 - who ever had the idea of getting Jim and Marilyn Lovell to do a commentary deserves hearty congratulations
Cruel Intentions - not very informative at all, but a lot of fun. Particularly listening to all the males in the recording getting excited by the central park kissing scene
Can't Hardly Wait - a stupid movie and an appropritately stupid commentary that is tonnes of fun to listen to
Das Boot
Go
Clerks/Mallrats of course
Out of Sight
Army of Darkness
Evil Dead
Mask of Zorro & Goldeneye - Amazingly informative commentaries. Martin Campbell seems to have something to say about everything.
Run Lola Run
City of Lost Children

Okay - I did mean for those to be in alphabetical order but I kept thinking of more worthwhile ones.