Deadpool

Essential within its own strand and effectively standalone. It is set in the same continuity as the X-Men films and goes out of its way to barely touch them, with two mutants from the mansion appearing as a running joke about the budget.

It exists because of a leak. Ryan Reynolds had spent years failing to get it made, test footage was produced and shelved, and when it appeared online in 2014 the reaction was large enough to force a greenlight at a budget of around fifty-eight million dollars, which is a fraction of what the X-Men films cost. The constraints are visible and used as material: a deserted motorway, a scrapyard, and a cast of about eight.

The structure is the smart part. It opens in the middle of an action sequence, freezes, and tells the origin in flashback while the fight continues, which gets the cancer-diagnosis material done without stopping the film. The romance underneath is played straight and is better than it needed to be.

The jokes to the camera are the selling point and the thing that dates fastest. Its real legacy is commercial: it demonstrated that an adult certificate was not an obstacle, which produced Logan a year later and a decade of imitations that mostly missed what made it work.