Good, unique writing that surprises me is almost always my ultra favorite, but.... fav cliches/tropes:

I like Tony's movieverse!robots and/or JARVIS as beings, and anything with extremis-like stuff. Man-with-a-plan!Steve. Any discussion/doing of art (Pepper and Steve both handy for this).

Also horribly weak to quantum mirror/alternate universe travels, genderswapped, turned-into-a-child, and sex-pollen and certain dubcon/noncon situations.

Also probably anything involving kittens, adoption of or transformation into.

/attempts to be shameless, but still feeling a little shame