I think most of the first-ed modules are embarrassingly crappy.
Keep on the Borderlands? ugh! I agree that
White Plume Mountain would make for some great visuals, but again, you have to totally ignore the (lack of) story. If it could be "punched up," then yeah, maybe that one.
Ravenloft is fantastic, but mostly because it's D&D that mimics Hollywood, so we like it a lot. If it were made into a film, it would be a film that mirrored a game that mirrored films...kinda weak, I think.
For visuals,
Lord of the Iron Fortress or the
Bastion of Broken Souls would make for fantastic CGI environments: the plane (withheld for spoilers) from
LotIF would be cool, I think. And while I would love to talk about the planes in
BoBS, I am soon going to run my group through this one, and one of the players reads this, so NO SPOILERS, please, thanks.
I'm going to have to say
Heart of Nightfang Spire or
Forge of Fury would make great films. Both have that classic "heroes go to stop the predation" hook.
HoNS has a nice pacing for lower bosses breaking up the action to final BBEG. With perhaps some borrowed Cthulhu-esque flavor it can really grab the viewer at some of the horrors found within. Despite the fact that the adventure can be a real slog if the PCs want to
Nike it, a screenwriter can gloss over that, and a director can montage-sequence it, eh?
FoF is probably the best bet, though: once the protagonists deal with the threat, they have this spooky environment to explore, giving rise to interpersonal "Guys, let's get out of here!" conflict, as well as the comically overpowered diplomatic situation that they have to solve in there (you know what I mean, and when I ran it, we got the hilarious denouement: "mmm! Donkey! I haven't had donkey in years!"). And then there's the rather terrifying BBEG. And, of course, being a low-powered module, I would guess that this is one of the easiest to make on a budget.
Yeah. I'm going to say that
Forge of Fury is my bet for best screenplay material.
