Here's my list in my lifetime of watching the NBA (started really following in the mid 1980s). This is my subjective opinion, not necessarily based on individual statistics or championship rings. These players are ranked in accordance to how great I think they were, regardless of statistics or rings and regardless of longevity, so Reggie Miller isn't going to be high on the list just because he played until he was 60 years old and Grant Hill won't be excluded just because his injury cost him a good 5+ years of his prime and LeBron James won't be downgraded because he's so young. This is greatness I've watched and seen and observed and witnessed. And, it's more about me being amazed by these players and what they were able to do on the court rather than their statistical output or number of awards.
Dr. J was right at the tail end of his career in the mid 80s. Although I know how good he was and have seen highlights and even games on ESPN classic, I didn't really watch much of him. He's not on my list because I didn't watch him enough in his prime. And, Kareem was at his tail end as well when I started really following the NBA. I left him off as well. Obviously, those two would likely be pretty high had I seen them both a lot in their primes.
1. Magic Johnson (I know many disagree, but I was more amazed by Magic as a player)
2. Michael Jordan (yes I hated him)
3. Hakeem Olajuwon
4. Shaquille O'Neal
5. LeBron James (slots 5-7 could really go in any order, imo)
6. Kobe Bryant
7. Tim Duncan (in part because he is so methodically effective, it's sometimes not so "amazing" to me)
8. Allen Iverson
9. Larry Bird
10. Charles Barkley
11. Isiah Thomas
12. Kevin Garnett
13. Dwyane Wade
14. Manu Ginobili (because of how he plays when it really matters in the playoffs)
15. Dirk Nowitzki
16. Vince Carter (his greatness didn't last, but when he was great, wow)
17. Chris Paul
18. David Robinson
19. Karl Malone
20. Grant Hill (looks like Piston bias, but I don't even like him as a player, but before the injury, he was that good)
21. Chris Webber (this is personal bias)
22. Dominique Wilkins
23. Penny Hardaway (what if?)
24. Patrick Ewing
25. Dennis Rodman (still amazes me what he was able to do with limited skill)
26. Jason Kidd
27. Tracy McGrady (I'm largely ignoring the injuries and him being a and going mostly on talent)
28. Tony Parker
29. Steve Nash
30. Dwight Howard
31. Clyde Drexler
32. Larry Johnson (another what if?)
33. Kevin Johnson
34. Stephon Marbury
35. Amare Stoudemire (dumb meets stupid, but still has crazy talent)
36. Tim Hardaway
37. Scottie Pippen
38. James Worthy
39. Reggie Miller
40. Ray Allen
41. John Stockton (I hesitated to put him on the list at all)
42. Chris Mullin
43. Chauncey Billups (never phased by the pressure of the moment, even when he failed)
44. Glen Rice
edit: I realized I left out Paul Pierce and he should probably be in there somewhere, but I don't feel like changing and rearranging it.
Some of my personal favorites who I thought were great in their day or had great talent but were not consistently great enough or didn't meet their potential and talent: Nick Van Exel, Walt Williams, Shawn Kemp (in his prime, insane)