Following is a list of cliches we've all see in science fiction:
After being removed from a place/artifact that prevents aging, the character's biological progress attains unbelievable speed and he grows old quickly.
All Aliens seem to understand human body language (ex shaking head), despite that even humans sometimes have difficulties comprehending the non-verbal communication when confronted with foreign cultures.
When ships lights on fire, the flames are visible in outerspace, even though there's no oxygen.
After a ship blows up its debris scatter, but don't damage any other ship despite being large and traveling at high velocities.
When a laser misses in space, it ends abruptly instead of continuing to go through space until it hits something else.
The entire Alien Species is united under a single ruler/ruling body, not having been divided into different countries or territories.
Post-cataclysmic rag-tag armies struggle to survive against gangs of bandits, mutants, cyberpunks, bikers, etc.
The Good Guys travel through time to stop a historical Bad Guy, usually Hitler.
Aliens travel a zillion miles to loot the earth of resources which exist in far greater and much more easily exploitable quantities on the many uninhabited bodies they pass on the way to earth.
Brain-controlling parasites attempt to wrest control of human race.
A great hunter decides that humans are the most entertaining prey of all, and visits Earth to bag a few.
The bureaucratic/reactionary mindset stands in the way of scientific progress. A researcher overcomes it through ability, purity of heart, and use of the scientific method. Or not.
A human male becomes pregnant.
An android discovers emotions and loses control.
Humans are seen as a menace to galactic society, having developed technology over a few short centuries compared with the thousands it took the other races.
Aliens whose thinking is so different from ours that no communication is possible.
Alien races that find our women attractive, while we find theirs to be repulsive.
Alien races who differ from us only in skin color and/or facial features.
Alien races whose names all have lots of hard consonants.
Lots of apostrophes are packed into alien words and phrases for no apparent reason.
Humans of future have no ethnic, religious, cultural, philosophical or political variance.
Planets with the same exact climate planet-wide (planets without atmosphere excepted).
Can you name a few of your favorites?
It always cracks me up that humans are always the most beautiful. Another
fave is how starships colliding or firing weapons make noise, when in fact
there would be none.
The apostrophe thing has always driven me nuts. I also find it interesting
that English is truly a universal language. It also makes me laugh that at
some point in the future, we are all supposed to discover that metallic
fabrics make for the most comfortable clothing. Obviously, the future is
not yet here.