"Greatness" is measured by the ability to lead a team to a championship. A guy can't be considered great just because he can score 50 points every game without a championship. My list of people are very good players in their own right, but also they must have the minimum requirement of at least 1 ring. Guys like Iverson, Lebron, Carter, Malone, Barkley, etc. are all amazing players with maybe better skill than some of the players in my list, but they cannot be considered great without a ring. Skill and statistics are secondary to winning.
1. Bill Russell - 11 rings, 5 mvps (finals mvp not invented yet, probably most of the 11)
2. Michael Jordan - 6 rings, 5 mvps, 6 finals mvps
3. Kareem Abdul-Jabbar - 6 rings, 6 mvps, 2 finals mvps
4. Magic Johnson - 5 rings, 3 mvps, 3 finals mvps
5. Kobe Bryant - 5 rings, 1 mvp, 2 finals mvps
6. Tim Duncan - 4 rings, 2 mvps, 3 finals mvps
7. Shaquille O'Neal - 4 rings, 1 mvp, 3 finals mvps
8. Larry Bird - 3 rings, 3 mvps, 2 finals mvps
9. Wilt Chamberlain - 2 rings, 4 mvps, 1 finals mvp
10. Hakeem Olajuwon - 2 rings, 1 mvp, 2 finals mvps
*Rank is based on priority: rings, mvps, then finals mvps.
*Russell only Celtic in the 11 championship run because he was the leader of all those teams.
*Michael above Kareem despite more mvps because Kareem played for 20 years, and some of those championships were from a Magic Johnson led team.
*Many players have more championships (i.e., Scottie Pippen with 6, Robert Horry with 7) but they didn't lead the team when they won.
*George Mikan not on the list despite 5 rings because he had very little competition in height and the mvp or finals mvp awards were not invented yet in his time, making it difficult to speculate his real value as compared to other players.