The 2006 film "Superman Returns" clocks about 2.5 hours, and by many viewers' standards, its a pretty long viewing experience as it is. Its not much of an action movie, and isn't for everyone, but...
People following the production closely noted that there were a lot of missing pieces from the final product that we'd seen in previews, stills, etc...
In many ways, I believe it may have resulted in a loss of context in favor of a run-time short enough to get more butts in seats. My understanding is that the final cut was approved and managed by director Bryan Singer, but there have long been stories around Superman Returns that Singer somewhat lost control of the production. So was the 2.5 hour version what the creators intended?
Superman Homepage has posted a story that several Super-Geeks have put together a petition for an extended cut, which they're calling "The Bryan Singer Cut".
Supposedly this version includes more footage of Kal-El's visit to the remains of Krypton, the interior of his spaceship, a lot more in Smallville, and probably other footage I don't know about. There's supposedly a new relationship between the windowed Martha Kent and Ben Hubbard, a guy mentioned in a single line (but never seen) in the first Superman movie.
I would love to see this version of the movie, and given that fan pestering resulted in the release of Superman II: The Richard Donner Cut, its possible WB could work with Donner and Co. to put together a lengthier version of "Superman Returns".
So... If you want to help out Supes, The League and the weirdness of Superman Fandom, you can click here to learn more. Beware: there's a blast of Super-Music when you click the link.