Love them or hate them there are a lot of common tropes across the science fiction genre. What are some of your favorite and least favorite tropes?
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.
Another trope I am not very fond of is nanotechnology where there are trillions of tiny robots that can effectively act as magic. It just feels like a lazy way to write science fiction because you really want a fantasy.
A trope I do actually like despite how overdone it is, is the idea of a precursor or forerunner. It often brings to light the absolutely massive scale of the universe which I find fun to think about.
Blindsight has something like that too, the Aliens are completely different from humans in that book. And its available for free if you're interested..
I also like how the Three Body Problem solves this issue (are there spoiler tags on here? Would hate to spoil part of the plot).
To add to that, there also Embassy Town by China Mieville. The Ariekei are so alien that they can only be understood by telepathically linked twins (since the Ariekei have two mouths speaking simultaneously).
Also, Eden by Stanislaw Lem is a classical sci-fi novel about a planet with alien life that's very different to Earth and stranded astronauts who try to make sense of it while finding a way home.