Stuff I like: 

• enemies to lovers
• contract and/or fake relationships
• grounded romance
• female falls first
• badass, self-reliant female leads
• Jung Hae-in (for obvious reasons)
• bossy or manipulative parents as central conflict

Stuff I don't like: 

• love triangles, polygons, trapezoids, pentagrams, pyramids, polyamory, or main leads cheating -- anything that isn't two protagonists who have exactly zero concurrent romantic interest or crushes other than the other lead; they can have exes who still like them, but not exes they're actively interested in returning to; I don't want to watch some fantasy of choosing between hot guys, leading people on, or 2ML getting stomped to pieces despite being perfect.
• over-the-top fantasy premises, like schoolteacher x 9,000 year old demigod spirit who likes her for no reason other than it's a fictional story and the director/writer said so.
• doe-eyed dumb female leads
• abusive or borderline abusive male leads
• rape or SA as a plot point