Tage Thompson?? Lmfao
In all seriousness though, the first 4 are pretty obvious: Gretzky, Lemieux, McDavid, Beliveau. But the final 2 slots are very difficult for me.
You obviously have the 3 M's: Mikita, Messier, and Morenz. While I think as a player, Messier may be 3rd out of them, his career to me seems to have been the best. He doesn't have the art rosses but he has 2 harts just like the other 2, 2 conn smythes, and 6 cups. I'd say he had the most successful career. I'd also say Mikita had a better career than Morenz simply because he played longer and racked up more awards/honors. Honestly, Idk how to contextualize Morenz's career so I can't say for sure but I likely take Messier and Mikita here if I don't think about it too hard.
Then there's Bedard. Obviously, he's still a question mark since he hasn't played a game, but as far as his prospect career's concerned, projecting him to be in the Crosby/McDavid tier is a fair assessment. If he ends up close to that, I think he'll finish as high as 4 on this list. My gut tells me he'll pan out, but I'd feel kinda crazy slotting him in there right now.
So I guess for now it's: Gretzky, Lemiuex, McDavid, Beliveau, Messier, Mikita. With Morenz as an HM and Bedard as a dark horse.