When a commanding officer scolds a subordinate: “YOU GOT THAT MISTER!” and he begrudgingly responds in the affirmative, rest assured, he most certainly does not “get that mister”.
It takes at least THREE attempts to start a car while being chase by a monster.
When the hero starts shooting a gun at villains, they drop like flies, racking up a huge body count. When the villains are shooting at the hero, they almost always miss. And when the hero does take a bullet, it always in some non-vital area.
Hey police work partner, why don’t you take it easy. You’re only three days from retirement.
I’m the master criminal’s girlfriend. I’m going to have sex with James Bond and promise to bring him some important evidence the next day.
Yeah, the two of us haven’t got along all movie but were stuck here together so we might as well try. Want to see a picture of my wife and kids?
If someone takes a blow to the head (frying pan), he will a) get up as if nothing has happened, b) have amnesia (which may be cured with a second wallop), c) NOT go to the morgue, DOA.
Well, duh. If she’s strong and intelligent, she’s not going to want an idiot in her life. At least, not as a romantic liaison.
When a feral child is rescued and socialized, they will always be able to speak perfect English and will have strange, animal-like powers that they gained through … err, osmosis, maybe?
All some dowdy chick has to do is take off her glasses and let her hair down, and she’ll be smokin’ hot!
They’ll probably start out hating each other, and won’t realize they’re in love until the last five minutes of the show.
This is known as “the soap opera rule” but it really applies to most TV and movies:
If you see the bride-to-be wearing the dress before the wedding, the wedding will be called off.
If the hero and heroine at a formal occasion (dinner, wedding, opening night) have to flee for their lives from the bad guys while still wearing their evening wear, at some point the woman’s expensive dress will have to be ripped up to make a bandage for the hero’s (non-fatal) wound.
But first, she has to tear off the material from ankle to knee so she can run in heels? 
When two crime-fighters part on the eve of a major development and one goes to get in his car, it’s a sure bet a bomb is going to go off as soon as he turns the key in the ignition.
As a corollary, the partner will be walking away and get knocked flat by the blast, but otherwise remains miraculously unscathed by it.
Montgomery Scott disputes this one.
Well, an uncredited actor. Uhura rarely got killed either.
Scotty himself was killed at least once, in The Changling. But he got better.
When there is breakfast, there will always be unfinished breakfast.
Hey, why do I, a Movie Mom, keep making these huge breakfasts when everyone rushes by, grabbing a quarter-waffle from a chin-high stack as they rush out the door?: “Sorry, mom, Hilarious Sidekick Nerd Friend is meeting me before school for a Soap Opera Plot Twist!”
When he gets into town with a bag of gold dust that it took him and his dead partner 4 months to cradle out, the bag he is holding will get torn and the gold dust will get blown away on the perennial stiff wind.
When Adam Sandler is in a movie/on TV, we know that irritating suckage will happen
“If a gun is on the mantle in the first act, it must go off in the third.”
Anytime a character’s face, especially a bad-ass character, is concealed, it will turn out to be a woman. This is especially true if the character is a motorcyclist.
If one of the cops/FBI guys/mountain climbers/deep-sea divers/investigative reporters has a pregnant wife, that guy is doomed to die. Possible twist: the partner of the pregnant one is also female. Still doomed, I believe.
Any former teacher/mentor/sensei beloved by the protagonist is similarly doomed.
If there’s an argument who goes through the door first, either way the argument goes the one who wins the argument will survive and feel guilty, because the other one will die.
If you pack a suitcase for your three-hour cruise, or take a cruise with someone who did, you will be stranded on an island for years with a bunch of other morons. But you will all survive.
When there is a cremation urn in a comedy, it will get spilled on the floor.