(From various Quora answers I wrote.)
Adding one letter to an existing title:
The Dark Knight Rinses—Batman finally takes a shower.
Irony Man—A two-hour montage of Tony Stark’s sarcastic humor.
They Truman Show—A documentary with some guys taking about Harry Truman.
The Hungery Games—A spelling bee between a bunch of attractive high school dropouts—only one can survive.
The Twilight Sagan: Eclipse—Carl Sagan talks about how cool eclipses are.
Furry—in WW2, a brave group of soldiers in fursuits fight a German Tiger (no, not a tank).
The Lord DOF the Rings—the Mordor Department of Finance tells Sauron his “Ring-plan” is too expensive.
Supperman—no one else can eat as much as Christopher Reeve’s character.
Supperman Returns—no one else can eat as much as Brandon Routh’s character.
The Ravengers—a courageous band of ravens save New York City.
The RAvengers—a courageous band of Egyptian gods save Giza.
Subtracting:
The Lord Of the Rigs—a brave group of adventurers travel thousands of miles to destroy an oil rig.
Project AIL Mary—a man wakes up amnesiac in a spacecraft. However, he learns he has great health insurance.
He Once and Future King—the story of King Arthur, told with terrible English.
LAS Babylon—the founding of the liberal arts college in Babylon is detailed.
Go of War—Polandball comics brought to life in a combat game.