Bad Santa
Went to Coney Island on a Mission from God… Be Back by Five
Harald and Kumar Go to White Castle gives you the beginning and the end but not much idea of what happens in between.
The Erotic Adventures of Candy
Candy Goes to Hollywood
No. He didn’t. He married the sister of an axe murderer.
My Stepmother is an Alien
The Exorcism of Emily Rose
Alien Invasion Tomato Monster Mexican Armada Brothers Who Are Just Regular Brothers Running in a Van From an Asteroid and All Sorts of Things - The Movie
Who can forget the Clive Owen/Paul Giamatti film Shoot 'Em Up?
I thought the main joke in this one was that John lives. However, the sequel, This Book is Full of Spiders, is closer to what the OP had in mind.
Bill and Ted’s Excellent Adventure is quite a good summary of the movie, as is Saving Private Ryan. Taxi Driver leaves out a few details, The Wolf of Wall Street has no wolves but the metaphor works, and How to Train Your Dragon pretty much is the whole story.
“The Persecution and Assassination of Jean-Paul Marat as Performed by the Inmates of the Asylum of Charenton Under the Direction of the Marquis de Sade”
Huh. . .see, I would’ve guessed that this title was metaphoric.
See post #6.
Wow. Me too. Thanks Miss Mapp!
Lots of great answers. Several I’d never heard of. Several duplications, but that’s okay. I’m usually the ‘movie guy’ in my circle, maybe it’s time for me to slink away. 
Thanks to everyone that has participated!
Ferris Bueller’s Day Off.
There are nuns.
They are nude a lot.
They use big guns to shoot bad people.
Yah, one impetus for starting this thread was the thought that most of the answers would be ‘B’ movies without a great deal of plot and development. I’ve been proved wrong in that assumption, but there are still a lot of movies like this. I can imagine this movie from the title, though I could always be wrong. Must research! 
They’re hoping this will really put their town on the map!
No, literally.
Just quoting this for anyone who needed a second dose to get the reference.
By the way, I once mocked up a still-in-the-original-package “My Dinner with Andre Action Figure” for a friend.
Also by the way, I do wish Andre had had more of a plot. Loved the conversation, but I kept waiting for something to happen.
So it does fit the OP.