Quinn, I'd say. She's pretty impressive in her old ongoing and her retarded Supergirl v5 cameo really overplayed her enhanced stats.
I'd say she's MKs physical superior, but he's more skilled. If she were to have some time to get dirt on him before the match I'm sure she could psychologically break him down like she did to the security agents at Arkham. In a straight h2h encounter she's just a hair better in my opinion.