Sakic, Jagr, Trottier, Yzerman, Forsberg, Bourque, Messier, all have good arguments for/against why they are better than Crosby. Sid is in that class, but he's not noticeably above or below it. And honestly, prime for prime, I take Lindros over Crosby. And that's only if we're discussing skaters. If we count goalies, Roy and Hasek are above Crosby without question.
And that's just players from the last 35 years. Beliveau, Esposito, etc, all have their arguments too. I won't even discuss whether he's above Gretzky, Lemieux, Orr and Howe. He's not.
This isn't to denigrate Crosby. Being in the class of the players I mentioned in the first line means he is almost certainly a Top 8-15 player more or less. Conceivably, he could be Top 5 if you think those players should be in the argument for Top 5. Personally, I have Crosby below Jagr, above Forsberg, somewhere between Sakic, Yzerman, Bourque, and Lindros. Pick any order you want.
One thing that stands out to me is whether a player was clear cut the best player in the league for consecutive years in his prime, and to me, Crosby has never been dominant to that level. Sometimes he's THE GUY. He's been THE GUY more than Ovie, Price, or anyone else of his generation. He has had the better career, no question. But discounting injuries, looking at all his healthy years, sometimes Crosby wasn't even the best player on his team. Some years Malkin was the best in the league, Ovie certainly wasn't looking inferior to Sid back when he was scoring 60+ goals, Price was no question the best two years ago, Patrick Kane had his moment, and now Sid vs. McDavid will be a debate over the next few. Last year's Conn Smythe was heavily disputed - could have went to Phil or Murray just as easy. Malkin could have won it this year.
My point? Sid's greatness is cumulative in the same way that Messier and Sakic's was. But year to year, playoffs to playoffs, it's never certain whether he's going to be the #1 player in the league. Without the type of depth Pittsburgh has right now, him and Malkin were both passengers watching a starless Rangers team crush their spirit two years in a row. From a fan's perspective, we were always aware when those two were on the ice, but never feared them, like they could single-handedly turn the game inside out. I would say that, as a fan, I feared prime Ovie and Carey Price way more, whereas Crosby is that consistent greatness where he just does everything right, and is super dangerous when surrounded with guys who can carry their own weight.
As opposed to Gretzky, How, Lemieux, Orr, Lindros...who turned average players into 30, 40, and 50 goal scorers. Teams didn't need to search for their linemates to find someone who could play with them. They made the people around them great. Sid? He makes his teammates' jobs easier.
I don't hate Crosby as a Top 5 forward, but you have to put him over A LOT of players who produced/achieved just as much as he did, many of whom played in the same era as one another, PLUS Lemieux and Gretzky right there, whereas until McDavid came along, Sid really only had two contemporaries, one of whom plays on his damn team. And it's not even all that hard to compares eras in most of these cases, considering that guys like Sakic, Jagr, Lindros, and Forsberg all played in their primes during the Dead Puck era, against some of the best goalies and stingiest defenses of all time, when penalties weren't being called like today. Most of those guys were contemporaries with Sid late in their careers, so this isn't like...comparing Syl Apps to players born after 1990 or something. Joe Sakic had 100 pts at age 37, same year as sophomore Crosby won the Art scoring 120 pts. These guys played the same game.
My personal Top 15, excluding anyone who played prior to 1980 (except for Orr and Howe, who I put in my top four on reputation)...
1. Gretzky
2. Lemieux
3. Orr
4. Roy
5. Howe
6. Messier
7. Bourque
8. Hasek
9. Jagr
10. Sakic
11. Crosby
12. Lidstrom
13. Trottier
14. Yzerman
15. Lindros
16. Brodeur
17. Forsberg
18. Chelios
19. Ovechkin
20. Hull
I'm sure I missed someone. If this list were based on the domination factor alone, it would look a lot different. Lidstrom would drop, Crosby would drop, Lindros, Ovie, Hasek, all would be way higher.
And again, this is not including most of the greats pre-1980, many of whom have strong arguments to be right above or below Crosby. All things considered, I don't think Crosby should be any higher than 8 or any lower than 15. Just one guy's opinion though.