I'll go first. Mine is the instant knockout drug. Like Dexter's intramuscular injection that causes someone to immediately lose consciousness. Or in the movie Split where there's the aerosol spray in your face that makes you instantly unconscious. Or pretty much any time someone uses chloroform.
Some romance tropes.
People doing creepy things and it being portrayed as romantic. Like stalking, or not taking no for an answer.
Love triangles. I spend a lot of time with polyamorous people, and would like to see more representation. and not like "a cishet monogamous person's idea". But even if you are monogamous, you can date different people for a bit before going all in on someone.