First of all, you need a Criterion edition. Screenplay to play comparison. Audio commentary with Stoppard, Oldman and Roth. Dreyfuss too, why not, let's go whole hog. If you want to, have a Director's commentary and a Cast commentary, or pile em together, depending on the fun factor involved.
Costume design sketches.
Deleted scenes and outtakes. And if there's any documentaries extant out there, we want them too. So there you have it. Welcome back to Trailer Mayhem, boys and girls. Because we just can't stay away.