This is kind of spite-y, to be perfectly honest. TV show Negan (which I am assuming is the one we are using here, seeing as it is him in the pic) has zero impressive combat feats to date. He's either killed helpless victims, or unsuspecting people. Quinn is a trained killer, who literally has decades worth of experience, and was a Regent (leader of a Clipper force) before becoming Baron. And he has actually bested people like the Widow (she only survived due to a conveniently timed tumor headache), as seen here:
And she herself has feats like this:
But Negan would get gutted long before Quinn strains himself enough to get a headache.
I'm not that big on the comics but, based on some of the things I have heard Negan do, I'd still give the win to Quinn. Negan is a tough guy in a world where most people are civilians turned zombie survivors. Quinn is one of the toughest SOBs in a world where the vast majority of the people are highly trained h2h/melee fighters, with borderline superhuman capabilities (well, excluding the Dark Ones, who are straight-up superhuman). Hell, some of the things some Badlands characters do are literally impossible in RL (like Sunny doing a triple aerial backflip from a stationary position).
But to elaborate more, the only 2 people who have managed to last more than a 2-3 blow exchange with Quinn, in a 1-on-1 duel, was Baron Jacobee and the Widow. And they have both shown that they are well above the average Clipper. And both were also shown to be inferior to Quinn, barring some plot intervention. And even the average Clipper follows a strict H2H/melee training regime, from the time they are children, as Colts, before graduating to full-fledged Clipper. In fact, the only non-Dark One character I would put above Quinn, based on S1, is Sunny (even though they never had a fair fight). But that's not a slight against Quinn, considering it actually took getting ganged up on by 3 Dark Ones to lay Sunny's ass out.