Best player of a generation, some times there might be two that can overlap to an extent. A requirement to be in the discussion for me is multiple Harts and/or Lindsey/Pearson's, atleast for players who have played in the modern era (as I think Harvey and Richard who have one Hart between them belong in the discussion, and especially Richard may have been victims of biased voting, Harvey was traded in his prime for trying to start a union to a bottom feeder). I do think team accomplishments do play into it, which hurts Ovi. Conn Smythe's help.
Here is how I'll break it down. Keep in mind the Pearson/Lindsey award wasn't created until 1971-72 season and Conn Smythe in 1964-65. The clear generational guys are Gretzky (9 Harts, 5 Pearsons, 2 Conn Smythes) Mario (3 Harts, 4 Pearsons, 2 Conn Smythes), Howe (6 Harts), and Orr (3 Harts, 1 Pearson). Past that it is debatable. The next group up for discussion would include Crosby (2 Harts, 3 Lindsey/Pearsons, 2 Conn Smythes), Clarke(3 Harts, 1 Pearson), Bobby Hull (2 Harts), Richard (1 Hart), Harvey (none), Beliveau (2 Harts, 1 Conn Smythe), LaFleur (2 Harts, 3 Pearsons, 1 Conn Smythe), Hasek (2 Harts, 2 Pearsons), Mikita (2 Harts), Ovechkin (3 Harts, 3 Pearsons), Phil Esposito (2 Harts, 2 Pearsons), Messier (2 Harts, 2 Pearsons, 1 Smythes) and Jagr (1 Hart, 3 Pearsons).
Realize, there are a hell of a lot of great players left off that list. From Brett Hull (1 Hart, 1 Pearson), Brian Trottier (1 Hart, 1 Pearson, 1 Conn Smythe), Mike Bossy (1 Conn Smythe), Ray Bourque (None), Denis Potvin (None), Lidstrom (1 Conn Smythe), Sawchuk (None), Roy (3 Conn Smythes), Glenn Hall (1 Conn Smythe), Malkin (1 Hart, 1 Lindsey, 1 Conn Smythe), Sakic (1 Hart, 1 Pearson, 1 Conn Smythe), Forsberg (1 Hart), Yzerman (1 Pearson, 1 Conn Smythe), etc.
Now, there is also generational prospects in the modern era, who are by far the best prospects who come along once every 5 to 10 years, and would be the easy number 1 pick in any draft that contained them in that time frame. That list consists of Lemieux, Lindros, Crosby and McDavid. In any draft going forward 5 years in both direction, there is no player who was viewed as a better pick at the day of their draft. Due to being so exceptional, they are viewed as players who without injuries could realistically dominate the league in a generational fashion. Lemieux is clearly a generational player, Crosby probably is, Lindros managed to win a Hart but had his career destroyed by injuries and didn't end up becoming one. McDavid is tracking that way, already possessing one Hart and one Pearson before his 21st Birthday.