Who is the best player at NBA?
It's very hard to say which player is the all time greatest because team mates are so important in the success records of great players. Each player has strengths and weaknesses.
If you want to go by success, Bill Russell who played just 13 years won 11 TITLES!
Most points would be Kareem abdul Jabbar.
Stephen Curry(if he stays healthy) will probably end up the greatest 3 point shooter, and most accurate shooter when not double teamed, of all time.
Kyrie Irving should go down as the greatest finisher when it comes to driving to the basket and finding a way to lay it in.
Shaquille O'neal probably the most powerful unstoppable player around the rim.
Wilt Chamberlain, Oscar Robertson, Micheal Jordan, Lebron James, Russell Westbrook, Julius Irving, Larry Bird, Magic Johnson, and others could all lay claim to being the best in certain areas.
Since the quality of defenses, offenses, competition, etc. have changed throughout the years, who knows who is the best. I don't believe there will ever be one best of all time.