I'd lean toward Kaprizov. Not only is he able to be productive while playing with pretty much anyone...he's also shown that he's able to elevate the production of other players around him in a way that i'm not sure the others can match.
Pasta also has that ability to be incredibly productive while playing with less than elite linemates, but i don't think he has the same ability to drag those lesser linemates up with him in the same way.
Rantanen is kind of a neutral on that, where he's clearly had a symbiotic thing with some of the linemates he's had...but seemingly not all with his somewhat weird fit in Carolina.
Tkachuk has a gritty, pesty quality that could make a case that he impacts the game in more dimensions, but i don't know that his offensive impact is at quite the same level as Kaprizov.
Marner clearly brings up the rear amongst this group. He's weirdly like an "elite complementary winger", which is a bit of an oxymoron, but that's more or less the way i see him.