IYO, what 1-3 session (one-shot games are ideal), GMless/GMlite Story Games have the most effective rules to pull together different narrative threads and create a satisfying coherent ending? I'm not talking about advice here, but rules. The type of GMless Story Games I'm talking about are those in which the players have equal roles in creating the story; that is, the players aren't simply advocating for their characters—they're playing their characters in order to create the best story, not advocate for them—and are also taking on the role of creating (together) the story whole-cloth as well. They are the writers of the story and the audience as well. Can you think of any games that fit the bill?
If not, can you think of rules that would be effective in doing so, that would be specific to these type of games?
Edit: Oh, I should probably qualify that I'm looking for universal Story Games that can create any type of story and don't have a preset setting or narrative path to follow.