Larry Robinson and I don't think there should be much argument. +/- is an immensely flawed statistic BUT he's by far the best in history with a +730. Only 4 other guys break 500 (Orr, Bourque, Gretzky, and Bobby Clarke). Of those only Orr and Clarke played fewer games (Orr played about half so his 597 is mindblowing in its own right). And it isn't like he just played forever he is only 34th in games played in history. He did play, particularly in the 70s with the most dominant team in team sports history with the 1970s Canadiens (in 1976-1977 when he played for the best team in any sport he was a plus 120 which is better than all but 150 NHL players careers) but he also played through the entirety of the 1980s in the biggest offensive era in NHL history. The numbers are just staggering. And he never had a minus campaign. He only had 4 years in 20 with single digits.
Now Lidstrom is great and the best of his era and I've loved watching him but he's already played more games and has also been on stacked teams throughout his career. Potvin or Bourque might go ahead of him for me but those would be the clear next 3.