I,too, have several favorites, but I think I can narrow it down to one or two per show.
NY: Anytime Mac and Stella are in the scene together, I adore them; not as exciting apart.
Miami: I loved Khandi's character and, of course, Yelina.
LV: LH and Cat, but even more so, I loved Cat's Dad, Sam Braun; isn't he the guy you'd want to have your back? NOBODY bothers you, then!