As someone who has a bucketload of favorite tropes/kinks, I've decided to narrow it down to just a few. I have some general tropes featured in any kind of storytelling medium, though most of them are centered around what you normally see in fanfiction.
Found family. This trope is by far my absolute favorite, it is the beating heart of what I most consume in media (Firefly, Dark Matter, Sense8, Critical Role, etc.), it is my ultimate weakness. The entire concept of family of choice is so inspiring and heartfelt because it all comes down to choosing the people who you want to surround yourself with, who you probably didn't intend to actually befriend and probably couldn't be more different from you, but somehow through particular circumstances find yourself forming a deep connection with these people, helping one another and growing together. One of my favorite version of this are the dysfunctional misfits who initially don't like each other and don't get along in the beginning, but once there is a trust and bond formed they are completely "ride or die" for each other and that? Is so beautiful to me. I eat it up every single time. I guarantee you, when done right, I will fall in love with any found family unit.
Redemption arcs. I'll be honest, good redemption arcs are hard to come by because I feel most writers tend to try and rush the process without actually dealing with the consequences of a character's actions and allowing that character to show that they are truly remorseful and work their way to amend those actions. What makes a good redemption arc, in my opinion, is showing them hitting rock bottom, realizing their wrongdoings and having them understand the ramifications of their actions while trying their best to better themselves. They may ask for forgiveness, but they never demand or beg for it, they never ask anything in return and they know that it'll probably take a lifetime to fix the damage that they've caused, but they are doing so because they truly want to make things right, for others and for themselves. A good redemption arc is showing, rather than telling, in a way that feels organic to the narrative of that character's story. I feel like the only redemption arc that felt remotely close to complete for me was Faith Lehane, particularly her episodes on Angel where she got the most development of her storyline.
Enemies-to-friends-to-lovers. When done right, there is nothing more satisfying than reading a fic that features this trope. This is probably why I love and have certain OTPs (ex: Harry/Draco) because it's where the attraction of why these two characters are intriguing together in terms of their history and where fic can further explore what canon could not in terms of these relationships. What happens when two characters who were once antagonistic actually end up reconciling and becoming friends? What happens when that friendship then turns into something more? It's so fascinating. Same with the friends-to-lovers trope, as well.
Sex pollen. I mean, the whole concept of "fuck or die" as a trope is mostly for the means of sexytimes and usually just in a PWP way of getting your OTP together, though honestly my favorite stories focusing any variant of this trope is the examination and exploration of the characters afterwards. From the angst of feeling guilty of taking advantage of the other character to questioning their own feelings about each other, and usually it ends on a happy ending note where they confront these feelings and talk about what happened to where they end up having emotional sex for real. While I don't mind reading just straight up PWP sex pollen stories, I find these to be more satisfying and compelling.
Pretend couple. Listen, to whole "pretending to be a couple" trope will never get old because it gives us such quality content. Your OTP or favorite pairing, who aren't together yet, have to pretend to be a couple for who knows what and for how long, and it creates an entire scenario about discovering those feelings for each other. Add in the element of mutual pining, another trope I love, and you get so much UST and angst until the eventual happy ending that they both deserve. It's a trope that I can read a thousand times over and over and never, ever get tired of it.
Praise kink. This has become a recent favorite over the years. It's pretty much the opposite of dirty talk (which I'm personally not a fan of when reading fanfic), and it's just basically having a character get really aroused by being praised. And I prefer characters who have this particular kink to be more on the self-loathing side, if that makes any sort of sense? Like, they probably put themselves down too much, don't think highly of themselves, or they're overworked in a thankless job and don't get the recognition they deserve. It definitely has a kind of dom/sub vibes in a way, though it doesn't necessarily have to be for me to enjoy the kink, I just love it for what it is regardless of the context. I don't know if I'm explaining myself in a cohesive manner, but to give a bit of reference, the first time I was introduced to this concept was through this amazing Bilbo/Thorin fic which explains pretty much everything on why I love this kink.
Wing kink. There is just something about characters who have wings or suddenly sprout wings by mystical/magical means, and the use of the sensitivity by means of eroticism of those wings in a fic to be very appealing to me for some reason. I have only read these types of fics with Dean/Castiel and probably a few Harry/Draco ones in the past, so it's not with every pairing.
First time / first kiss. When written well, the descriptions of how a character is feeling in regards to their first time or first kiss is probably what I love the most in any story where my OTP is getting together, because their emotions are heightened from being super nervous and not knowing what to do with themselves just from being so overwhelmed and overcome with pure emotion and love for the other person. The simple description of how they feel after their first kiss, to getting to their first time, it's probably something I really enjoy when I read a really good fic that features either or both. I find it absolutely adorable and it makes me smile whenever I come across it.