Goalscorers have short peaks, and I think their time at the top and consistency at the top, is more important than overall consistency at a "good" level in terms of judging them. So someone like Iginla who has 2 Rockets, but only 2 other top 10 seasons isn't going to be that high due to a ton of seasons in the 30s.
As such, it's Stamkos for me. His peak window was just better than Kovalchuk overall. 5 top 2 finishes (in 6 years), compared to 2 top 2 finishes. Kovalchuk does have 8 seasons in the top 10 compared to 6 for Stamkos, but I don't think a slightly longer prime makes up for Stamkos' peak and extended peak advantages.
After those, it's Iginla, then Crosby, who could arguably be above Iginla. Both have 2 Rockets, and 2 more top 10 finishes, but Iginla's first Rocket peaked higher and his two other top 10s are better. Still, they're both players who were generally in the 30s with a few spikes, both have big goal scoring playoff runs and Sid looked like he would have the higher peak in '11. Iginla's longer career probably puts him ahead for now, but I think Sid will pass him.
After them, I'd say Malkin, who is a bit underrated due to injuries. Despite them, he still has 3 seasons in the top 5 in goals (more than Crosby and one less than Iginla), and 5 seasons in the top 10 in GPG (all top 6, same as Iginla). Overall, he's paced for just under 39 goals per 82 games over his career, which is just barely under Crosby who paces for 39 on the nose. He also has some big goal runs in the playoffs.
Next I would say Perry. His Rocket puts his peak ahead of Hossa, and he has another 2nd place finish as well. Hossa's best was a 4th place finish, and Perry has one more top 10 finish than Hossa as well (5 to 4).
Sedin is clearly last. Only 1 40 goal season, which was his only year in the top 10 in either goals or goals per game.
So it goes:
Stamkos
Kovalchuk
Iginla
Crosby
Malkin
Perry
Hossa
Sedin