And, of course, it's easy to do it with science-fiction films as well. "Disaffected farm boy destroys military installation, killing thousands" is, for example, an accurate but misleading description of Star Wars, giving the impression that it's a different kind of film than it really is.
With that in mind, here are some accurate but misleading descriptions of popular science-fiction films. Enjoy. (And if you feel so inclined, add your own in the comments sections)
Back to the Future
A bewildered teenage boy fends off his mother's disturbing and unnatural attraction to him.
Star Wars: Episode I - The Phantom Menace
A speech-impaired alien and two priests attempt to acquire a small boy on a bet.
The Matrix
A lonely programmer discovers he is spending more time in a massive multiplayer online game than he ever suspected.
The Thing
A visitor tries to blend in with the crew of an Antarctic base but finds attempts to become "one of the guys" is met with suspicion and resistance.
2001: A Space Odyssey
A well-meaning computer's attempt to fulfill its mission runs afoul of a human crew with other plans.
Alien
A rambunctious alien child invites itself aboard a human cargo ship; a memorable game of hide-and-seek follows.
Avatar
A company attempts to solve the Earth's ecological woes; unhelpful aliens interfere with the task.
Blade Runner
Poor product design leads to trouble for a manufacturer and one exasperated policeman. (Note: this is also the description for I, Robot.)
Cloverfield
A group of hipster Manhattanites find their plans for the night completely overturned thanks to an unexpected visit from an out of towner.
Inception
An eclectic group of dreamers meet a poor little rich boy and try to change how he feels about losing his father.
Jurassic Park
A group of people go to an amusement park but are hampered by bad weather and faulty ride management.
Men in Black
A cop joins the immigration service and loses his sense of identity and his place in the universe.
For the longer list, click over to AMC's Filmcritic.com.
UPDATE: Here are some of the funny Comic Book Movie ones from users...
Spider-Man:
A young nerd discovers that venomous spider bites are actually a good thing.
Batman:
A rich orphan exhibits some psychological "issues" and a strange fixation with flying rodents.
Superman:
Your typical alien invasion story without all the spaceships and stealing of natural resources.
Green Lantern:
A man discovers he likes wearing jewelry, tight fitting clothing and space travel.
X-Men:
A bald cripple opens a school in order to attract young kids with "gifts" that will fulfull his every desire.
Captain America:
A 4F weakling takes performance enhancing drugs to get into the army.
Incredible Hulk:
A man evades anger management to pursue a career bottling soda in the 3rd world.
Batman & Robin:
A gay couple show off their rubber S&M outfits. That was pretty much the plot, right?
Iron Man: A genius billionaire finally discovers the solution to the world's energy crisis, potentially bringing about world peace and global economic prosperity, but instead uses it's power to host totally rad parties.
Ghostbusters:
4 men who live together and try to clean up what they call 'ECTOPLASM'.
Superman:
An alien invader builds a house in the arctic, romances a newspaper reporter, and matches wits with a real estate mogul.
Jonah Hex: Disfgured Cowboy attracts trashy whore despite losing his cheek to cancer.