I am not sure what games specifically you consider to be in this genre, my definition is most likely different to yours.
What I like most is player choice and for the choices to have consequences. Ideally there are no clearly right or wrong choices. Good combat, for me this would be like the ME trilogy or FO4. I prefer fully real time or at least RTwP. Companions that feel like actual people, not followers, ME trilogy was my favourite for this. Open world is great. Decent graphics and and option for third person view also give me proper immersion. A good story is nice to have but I can forgive it being shallow if the combat is good or I can make my own story.
Things I care nothing about would be music and romance. I might like the music when not playing the game but I find a constant soundtrack to everything immersion breaking and repetitive, and I just don't see a point to awkward pixel sex (also I usually play characters that have other priorities.)
