Batman (He’s simply knows everything in terms of hand to hand combat)
Daredevil/Wonder Woman (I’d imagine Daredevil would be high up their honestly my ranking could be wrong. Diana however gets her skill brought up time and time again)
Black Widow/Taskmaster (Skilled to the extent of performing impressive feats against fodder or characters with a stat advantage over them, but not among the most skilled)
Captain America/Deathstroke (I’d imagine they are skilled but a lot of their fights against other skilled opponents rely on their equipment or super soldier stats are put in play and then often times their equals to people physically weaker than them because of their stats)
Aquaman (He’s shown combat skill but the extent to how skilled or how competent of a fighter he is isn’t as fleshed out as some of these other characters, i ironically feel the movie did a better job with highlighting his training then the comics ever did)