oh i've never sat down to think about this that's interesting. i think there's a very boring but right answer i could give (it all depends on what the text is trying to do and i like when the style changes to meet the pacing) but going off my own preferences i'd say i'm drawn to observational writing that's less guided by the plot and more by the character's thought process and emotions. can't think of fic examples but murakami and alice munro do this perfectly.
i enjoy highly descriptive language so turns of phrases or analogies always catch my eye. anyone can come up with a good one liner but actually fitting it into a story and having it serve a purpose is a different thing. i also like a slower kind of pacing so i know i'll like it when details are the main event and action comes after the scene is laid out for me. not necessarily in the tolkien way of "welcome to this book here's 10 pages of exposition before we go on with anything else" but moreso in the way where the writing doesn't leave the immersion completely up to me and guides me through it, like this is how this smells and how the air feels and this is how this room is laid out and here's how it is inside this character's body right now, and also here's why this is all important and it's not just needless trivialities. observation with purpose, if only to draw my attention to the smallest of things so i can appreciate it or see it through someone's eyes and then move on.
i really value when i can understand characters from the get-go as well. going into the first paragraph and getting an immediate sense of their humor or their judgment or some key part of them gets me hooked immediately.
i hope this makes sense and i'm not rambling but i guess tldr i like writing that lets me feel like i am peeking into someone or something's life. fly in the wall writing if you will