Either a silent film (jk), or a musical. As much as I don't care for most musicals, that option probably makes the most sense. If not a musical, then maybe a music-based movie... like Spinal Tap. Or maybe one of the Police Academy movies, like 3 or 4, so then you'd have to deal with motormouth Jones' sound effects, and Bobcat's grating voice.

I watched The Hateful Eight for the first time recently. Due to how dialogue heavy it is, I was thinking it'd probably work as a radio drama. It's not just that it's dialogue heavy though. The great cast made the dialogue feel important, even when it really wasn't. That or something similar in terms of dialogue and casting would probably be a good choice. A strong soundtrack would be important too, which The Hateful Eight also has. I'm not sure it'd actually be the movie I'd choose, but it'd definitely be one to consider.

I always figured Dark Shadow would work well as an audio series.

Session 9...Hands down.
Resolution...distant 2nd.

Ballz broke it down for us. The movies you'd pick would have to have great dialog, a great soundtrack, or both.

The Lost Boys comes to mind, for the soundtrack. Also anything that Goblin did the music for. Dawn of the Dead (1978) in particular would be really good.

Also, maybe Phantasm (1979)?

I also think of Bug (2006), which I think has great dialog. It's like a play, somehow. I bet you could listen to that whole thing and get a lot out of it.

Also, anything you have seen over a dozen or so times already, just because you don't even really need to glance at the screen, you can picture everything already.

Cemetery Man, AKA Delamore Delamorte, would be a good one. It has a LOT of really good lines that are worth listening to. It's excellent visually too, of course, but you would get a lot out of just listening to it... I might actually do this, now that I'm thinking it over.

A Quiet Place would be really, really, really good. No, kidding, of course.

How about Omen 3: The Final Conflict? I'd have to think about this one some more, but I remember it has some interesting long speeches and soliloquies by Damien.

Frailty would be a pretty good one too.

Without a shadow of doubt... "The Man from Earth (2007)" I have easily listened to this 50+ times to get to sleep (the film is great though) it is all dialouge and you can just listen to it like an audio book.

I'll have to check it out. I've been looking for a new sleeping movie.

Defo try it & let me know what you think.... obviously watch it normal first though.