Since I had nothing to do the last 30 minutes I took a look at this. I just looked at each players best and second best season in terms of pts, obviously there are many more factors that play in. For example I would say the Bergeron was and is a much better player at 24+ years than before even though his best pts seasons were at the age of 20 and 21. Also, a few players on the list are still young and could improve.
Players included: Crosby, Benn, Spezza, Jagr, Stamkos, Giroux, Kessel, Kane, Thornton, Seguin, Eberle, Kopitar, Ovechkin, Backstrom, Tavares, Bergeron, Getzlaf, Perry, L.Eriksson, Krejci, Hossa, Datsyuk, Toews, Zetterberg, Nash, Malkin, Hull, Shanahan, Gretzky, Tkachuk, Modano, Sundin, Lindros, Sakic, Forsberg, Kariya, Selanne.
edit: the players in bold had their best season under the age of 24 (I know, Seguin and a couple more are probably too young to be counted).
Age 19: 1
Age 20: 5
Age 21: 10
Age 22: 13
Age 23: 12
Age 24: 11
Age 25: 5
Age 26: 6
Age 27: 5
Age 28: 2
Age 29: 1
Age 30: 1
Age 31: 1
Seems to be a relation as well to draft position. Players like Datsyuk, Zetterberg, Hull, Alfredsson peaked much later than high picks and they bring up the average quite a bit so it could be interesting to divide this more based on where the players were drafted.