Science Fiction

A trope that I hate is that every alien planet or moon has the same gravity as Earth. Yes, I love The Expanse.

Bonus round: planets with one biome: ice planets, forest planets, storm planets. I left out desert planets, praise the maker.

That almost every alien species is bipedal and hominoid in shape.

A trope that's bothered me more and more over the years is planetary chauvinism. So many science fiction settings make the assumption that people will only ever live on planets - and usually specifically Earthlike planets - and anything else is just something for a mining ship to visit, when it's even thought of at all.

A somewhat related issue is the grand importance that Earth always seems to be given. I can understand it from the perspective of writing stuff for the general audience, it's super easy to make them care about whatever's going on by saying "oh no, Earth might be destroyed" but once we're a couple of centuries or millennia into being a spacefaring civilization with colonies all over the place Earth is going to be just one planet out of many. Star Trek is a particularly bad offender here since not only should there be plenty of human colonies just as big and important as Earth at this point but there are dozens of nonhuman Federation members too. The Federation didn't end when Vulcan got destroyed, it shouldn't end if Earth gets destroyed.

One of the worst examples of the Deus Ex Machina has to be Battlestar Galactica.

What do you mean with the idea of a precursor or forerunner?

It's silly, but one of my favourite tropes is the obligatory Groundhog Day episode that usually happens when a series goes for long enough. Among all the great episodes of SG-1, Window of Opportunity is one of my favourites. I know Farscape and TNG had them as well.

I think it goes without saying that one of the least favorite tropes is Deux ex Machina. I couldn't quite put my finger on it at first, but after watching the German TV show "Dark" I was utterly dissatisfied with it. The entire series up until the very last episode is about this inescapable time loop and alternative universes which is pretty cool while watching it, but then you get closer and closer to the end wondering how they are going to solve this impossible problem. Then surprise they just do it instantly in the last episode.

Except they didn't just do it in a single episode. If you watch carefully, you would have realized that Adam & Claudia had been working their whole lives to get up to that point. None of it appeared out of nowhere, even with the fact that the climax happened in an instant.

Honestly this thread went through a lot of ones that I love/hate but one trope I can't get enough of is "the aliens are uncaring" like in Roadside picnic where they show up, throw some trash down on earth, and leave. They are never seen or heard from, they don't even bother with us in the book.
There is another series with a deus ex machina where some AIs evolve into godlike beings and then just mysteriously leave, but I forget the name of that one as well.

I fell in love with an book series called Expeditionary Force, the first book Columbus day hooked me. It's fun, it's interesting, and the writer does an amazing job making the technology being discuss sound realistic and not too far fetched.

With that being said, ExFor has ruined space battles for me in Sci-Fi and made me realize a trope we all just took for granted - The Dog Fighting type of close combat you see in ship to ship battles in Sci-Fi. There just isn't any way that would ever play out that way, instead combat would happen at ultra far ranges, so far apart, that railguns could be dodged, even lasers and other high energy beam weapons could be evaded just by moving out of the way as light crawls along. Combat would be about bracketing your target with fire, and ultra fast, high g smart missiles.

Space is so insanely large, that you'd never see dog fighting like in Star Wars.