I can't really do so much more than listing Mary's excellent points from her earlier question as criteria for good list questions:
Constructive subjective questions are welcome on Movies & TV S/E.
Constructive subjective questions:
- inspire answers that explain “why” and “how”
- have a constructive, fair, and impartial tone
- elicit answers that can be backed up with facts and references
- have the potential to add to someone's enjoyment of a movie or TV show
- are not open-ended or hypothetical
- are likely to result in a possible "best answer" though multiple answers may equally contribute to answering the question
Questions that are likely to elicit a list of opinions that are not backed up by facts or references will be placed on hold
until they are edited to be more useful to the community.
Not a good match for this site: Who is the best actor of all time? (opinion)
A better match: The film 8 Mile about rapper Eminem is said to be semi-autobiographical. Which parts of the film are factually accurate?
Not a good match for this site: How is the color red used symbolically in films? (too open-ended)
A better match: Birds show up in a lot of Hitchcock films. What do they symbolize?
Though, they are rather about subjective questions in general and not so much about list question specifically. But in fact to me the more "blurry" kind of list questions are the ones we should prefer over rather trivial things like "list all underwater compound movies!" or "what movies feature a spyssassin on the run?". Those latter kinds of list questions can, as atticae already states, easily be extended ad absurdum and don't really provide any more useful information than IMDb or a similar encyclopedia already does. What I rather want to see are question that encourage explanation and reasoning over just listing, the why over the what.
And this is also the reason why I would strongly object to single community wiki answers to assemble such lists, since those answers are best placed on rather trivial list questions that just ask for a simple list of many bullet points that can be freely extended, which I would deem off-topic. A question that encourages more explanatory answer over mere statements, should generate answers that are timeless on their own and can stand on their own based on the reasoning of their argumentation, even if they might not be the only correct answers. Putting such answers into a single pile of CW robs them of any kind of individuality and the ability to asses them each individually based on their arguments (this is not about the posters' rep here, but about the posts' votes as a sign of quality). Once an answer cannot be judged as being "better" or "worse" than another answer, even if there might not be a single "correct" one, the question is a too trivial list to me.
But alas, this is all very blurry and I cannot provide any clear guidance to this matter. I tend to think that once we restrict that problem too hard and definitely, we will only result in the rather trivial kind of item lists as the allowed ones, which I would object to. But I also understand that some line has to be drawn. But you want examples, here you got some, even if I don't think they're too conclusive on the matter yet:
Have there been other cinematic crossovers like the Marvel Cinematic Universe?
This is a less listy example and more of the "is there any..." kind, but I feel they are quite closely related and sometimes a list question can be improved or made more definite by transforming it into that kind.
What are the methods of including a character's thoughts in an audiovisual medium?
This is inherently a list question, I think. It might not be perfect and the answers might not be perfect yet either. But I feel as long as the answers keep rather to explanation over just listing, it can very well work. And I don't think putting them all into a single post and slamming a CW sticker on that would really improve anything here, no matter if that would make it easier for the asker to accept a single answer.
Looking for a film about handling sadness to compare to the novel Norwegian Wood by Haruki Murakami
This is a difficult one, since it is in itself a recommendation question and I agree that opening that box comes with more than a handful of dangers. But I also think it shines by being well-worded and not too open-ended and also ecourages rather explanative answers. Of course assessing the quality of each and every question manually is way harder than having a clear-cut guideline, but such kinds of recommendation questions could possibly work.