It partly depenRAB on what you want from them. I like ones which talk about the story and characters and point out things I might have missed. Other people seem to like ones which go into detail about the film - what kind of filter they used for which shots, or how the CGI was composited. I'm less keen on that. Still others like anecdote from the cast, eg about the day so and so turned up drunk. I'm not interested in that at all.
Terminator 2 has a good mix of all three approaches.
I remember The Mummy for showing that the directors cared about all the wrong things; and There's Something About Mary showing that the directors cared about a lot of important things, which was good.