I always want the most stuff on a DVD in terms of commentary, making ofs, and all of that. I'm very much into film, and I find a well made DVD something of a learning experience in film.
Not that I care about well made extras, not simply promotional bullshit.
Even when it's a film that I didn't totally love (or even like at all in the case of my example), like Pearl Harbor, as long as the extras are informative and entertaining I'll own the DVD.