There was recent talk about whether Dirk Nowitzki is one of the ten greatest players of all time. As the discussions started, the conversation always turned to "well, who do you leave off?" your Top 10.
That's not how it works. Because of the caliber of any of the top 20 or 30 players of all time, in any sport, you can never make the case that their credentials mean they should move down on the list. People make top ten lists by forcing their way on, by being someone you can't leave off.
I don't know enough to have a top ten list, and I usually have idiosyncratic choices anyway. For example, in any sport I want to know if this is for one game, one playoff run, one season, ten seasons, or whole career, because my choices are different. (For one season or one playoff run, I'm playing Bill Walton at center - over Russell, over Wilt, over everyone. For his career, he may not be in my top ten centers.) But Dirk Nowitzki this season and these playoffs had that sort of run, where you start asking "how can we sanely keep him off" rather than "which player deserves to be cut?"