I don't know if I should reply to this thread because I'm not a big fantasy reader. I'm the fringe audience, at best. What I like in fantasy are elements of the horror genre. The evil power of the Ring. The zombies-whatever in Game of Thrones. Just thought I'd share in case you fantasy authors find it useful. I would also add that I'm beginning to hate dragons because I'm so truly, truly fed up with them, but I'm the minority so I don't think you should mind me.
With most genres good plot and character development are essential. For fantasy I like a sense of realism, regardless of the universe created. I very much dislike blanket "magic" fixes everything or blanket statements from the author without any backing. "The M.C. was intelligent, brave, handsome, and the best warrior in the kingdom." Then he comes off as an immature sexist jerk. I don't mind following standard tropes, but love twists on old ones. New concepts on dwarves, elves, trolls, goblins, etc. I love newly created flora and fauna as well. New planets, different evolutionary paths, etc. I love seeing a good authors imagination come to life. Unfortunately, lot of bad fantasy books out there for us KindleUnlimited readers.
I love seeing magic that doesn't completely break the laws of physics. If a magic wizard dude throws a fireball, that energy better come from somewhere because law of conservation of energy. I also love seeing applications of magic within the universe - stuff like magic agricultural equipment, domestic "technology", military stuff, etc. For example, pneumatic ballistic weapons powered by air or fire magic. Speaking of magic guns, it's always nice to see fantasy politics built around these speculative mechanics, such as issues concerning magic weapon control and the ethics of using magic.
Dunno why, but I really like seeing the protagonist doing some morally questionable things. There's something about blurring the lines between good and bad that makes my hair jump Also, medieval politics. I played too many strategical fantasy/renaissance/medieval, so when the author messes something up, it really throws me off balance. And, as @ToBeInspired (is that how you tag people here?) said, keeping things realistic. So when I see something like "They all lived happily in one country, and then there was a war with the gods, and then the gods died, and there was seven of something that had these keys, and now our hero on a white horse needs to find them", it immediately throws me off. I don't have a problem with cliche's, but I do have a problem with laziness.
I. Loved. Doctor Strange. So when the climax started, I was embarrassed by how easily they were resolving the villain's plan: Spoiler The Sorcerers' final Sanctum had just been destroyed and Dormammu was swallowing the Earth into the Dark Dimension, but Doctor Strange reverses time and we see the Dark Dimension being driven back and the damage to the city being undone. Boring. Just snapping his fingers and basically literally telling the narrative "that didn't happen." But then he said the, ahem, magic words to the other sorcerers Spoiler who are seeing the time-reverse with him instead of being swept along by it: "As soon as we rebuild the Sanctum, they will try to destroy it again." That was perfect. I actually define magic in my book as explicitly being "any natural phenomena which violate the laws of Conservation of Mass/Energy/Momentum..." but yes, the more blatantly a mage violates any law of Conservation, the harder it should be to do it.