Making one good movie sequel is hard enough, but a quality third film in a franchise, where countless possibilities have already been exhausted? It's a huge challenge.
While there are a few outliers, such as Indiana Jones & The Last Crusade, Harry Potter and the Prisoner of Azkaban, Lord of the Rings: The Return of the King and Toy Story 3, all of which lived up to if not exceeded the original, they are very much exceptions that prove the rule.
Movie studios love trilogies, and will put pressure on filmmakers behind two successful movies to quickly churn out a third sneaky milk of the cash cow, so it's not a shock that so many of them ending up disappointing audiences.
That doesn't make it sting much less, though, especially in the case of these hyped-up and promising threequels, which sadly fell rather short of the standard set by their predecessors. They're not all strictly bad films by any means, but it's hard not to look at them and see nothing but a blown opportunity...
13. X-Men: The Last Stand
The Originals: Bryan Singer is largely credited with bringing the comic book movie into the mainstream with 2000's flawed-but-thrilling X-Men, before following up with 2003's X2, which remains a high-point for the genre.
The Threequel: Singer unfortunately sat out The Last Stand, opting to shoot Superman Returns while Brett Ratner was brought in to helm this extremely underwhelming third effort.
The Dark Phoenix storyline gets a highly dissatisfying payoff, there are way too many subplots, Cyclops dies off-screen, Xavier is killed only to be weirdly sorta-resurrected in a post-credits scene, and it was simply an overall misguided attempt to one-up X2.
Thankfully Singer's recent Days of Future Past jettisoned it from the continuity in the most brilliantly passive-aggressive way possible. Good riddance.