That's a tough one, I think Bergeron and Kopitar are probably better offensively than their numbers have indicated over the years
Kopitar in particular, offense hasn't usually been the King's bread and butter and he's still led them in points most seasons
Barkov's put up better offensive numbers but I dunno, prime Kopitar was a two-way monster, Bergeron's arguably the best two-way guy ever
Kopitar's also the only guy with more than one cup, and if not for Bergeron he'd probably have more than two Selke's, he should have also been a Conn Smythe winner
As of right now I'd take either prime Bergeron or Kopitar over Barkov though