Madagascar: Escape 2 Africa: Paramilitary group leads the four friends (plus two of the "MOVING!" people) to another wild place. Among the problems they face are... tourists.
Madagascar 3: Europe's Most Wanted: Four friends gently strongarm paramilitary group to get them home and all involved get into the circus business while an insanely determined animal control officer is literally after their hides.
Madhouse: Iconic horror actor is stalked by his most famous character.
Man on Fire: A washed-up, world weary ex-hitman meets a little girl who makes him see the brighter side of life. He then goes on a killing spree.
Mars Attacks!: Aliens with a cruel sense of humor are thwarted by a Slim Whitman song.
The Martian: Man is left behind by his workmates on remote and deserted place, is forced to spend years waiting for them to return.
Mary Poppins: Children neglected by their workaholic father and political activist mother befriend a busker, participate in magic with their flighty governess, and cause an economic crisis. It's a musical.
Alternatively: A man learns to bond with his kids.
The Matrix Revolutions: The killer robots' existence is menaced by a man whose previous work include a drag queen and the voice of a sheepdog.
Mean Girls: A girl raised in Africa by her zoologist parents goes to high school for the first time and learns that American high school isn't all that different from the jungles of Africa.
Meet Dave: A starship tries to adjust to living in New York.
Meet the Robinsons: An orphan kid is kidnapped by a kid from the future, meets his relatives, and is then captured by a goofy man with a sentient bowler hat. ImmenseTimey-Wimey Ball and self-confidence aesops ensue.
Megamind: A man learns what life is like after overcoming his rival.
Memento: A forgetful, tattooed man kills another man for something he himself did. This probably isn't the first time.
Alternatively: A very important film to remind us that amnesiacs make terrible investigators.
Or: Maximus chases Wolverine for his entire life over some bread. Along the way, Wolverine adopts Catwoman's daughter. Borat and Bellatrix Lestrange try to rob him. Eventually, they all get involved with some students who have blocked off the roads (an action which gets a horrifying number of people shot). Nearly everyone dies, though the only really villainous character survives and thrives. It's a musical.
The Misfits: A beautiful divorcee hangs out with three selfish assholes in Nevada.
The Mist: Unusual weather phenomenon and wildlife sightings annoy supermarket patrons.
Bad weather keeps locals indoors.
Moana: Egotistical musclehead is forced by teenager to return a rock he stole once to its rightful owner.
A guy is forced to make up with the woman he dumped.
A young woman doesn't get along with her dad and leaves her village. Along the way, she joins up with a sailor who can't swim. A lady who's really good with geology is apparently the source of the village's problems. Also, we learn that a wrestler can sing quite well.
Modern Times: A man's job drives him insane, and he has to make a living thereafter.
A man has a nervous breakdown, loses several jobs, starves, and is unjustly imprisoned, all the while openly pursuing a relationship with an underage girl. This is supposed to be a comedy.
The Monster Squad: A bunch of foul-mouthed pre-teens hang out with Frankenstein's Monster, fight an old European man and his creepy friends, and discover the Wolfman does, in fact, have nards.
Monsters vs. Aliens: After a woman's wedding day is interrupted by a falling meteor, she's drafted by the U.S. military to fight a hammy tentacled alien. She works alongside a boastful fish-man, a half-cockroach Mad Scientist, a dim but lovable slime heap, and a very large grub.
Monty Python and the Holy Grail: Man is sent on a wild goose chase for a mythical artifact while his he friends get roped into the affairs of a bunch of weirdos.
Monty Python's Life of Brian: Guy mistaken for the Messiah joins violent left-wing front, gets a Latin lesson at sword-point, meets a government official with a speech impediment, and dies hearing cheerful song.
The Muppet Movie: A short guy who plays the banjo is convinced to go into show business. Along his way to Hollywood, he teams up with a struggling comedian, a portly, bad-tempered would-be actress who knows karate, a plumber with a chicken fetish, and other oddballs. He also has to avoid a restaurateur who really wants the short guy to be his new spokesperson.
The Great Muppet Caper: A pair of twin brothers who don't look anything alike reporting for a newspaper go, along with their oddball photographer, to England to investigate jewel robberies done to the local fashion designer. A would-be model pretends she is said designer to score a date with one of the brothers and is then framed for the robberies.
Mystery Men: A working-class stiff who beats people up with a shovel, a Fake Brit who throws forks around, and a hot-headed jerk accidentally kill their hometown's greatest superhero. They decide to save the day in his stead with the help of an annoying black teenager, a girl who carries her late father's skull around in a bowling bag, and a flatulent Pee-Wee Herman.