personally I think it depends on the storie and context, example:
suicide squad, the girl should have died, it's an R, it's in the real world and there should be consecuences >:C- sad
Supernatural- Should have ended with Sam in the cage and Dean free, right now it's just a parody of its formal self (though it's still a great show just not the same supernatural as in the start C:) -bittersweat
Pokemon- ASH BEATING A FRIGGIN TOURNAMENT!!!!>o< - Happy
ending note Happy stories need happy andings and sad stories should have sad stories, it be jarring if a happy movie like finding nemo ended with the father dead or something 