It took some good thinking but I made a list of the top 5 players of now, all-time and other greats.

Now
Point Guard: Allen Iverson-Hate to say it, but he gets the nod.
Shooting Guard: Kobe Bryant
Small Forward: Michael Jordan *Will never pick anyone over him*
Power Forward: Tim Duncan
Center: Shaquille O'Neal

All-Time
Point Guard: Magic Johnson- he and Larry Bird changed the game, before MJ.
Shooting Guard: Michael Jordan- his natural position.
Small Forward: Larry Bird- *See Magic Johnson*
Power Forward: Bill Russell- played center but HAS to be on this list
Center: Wilt Chamberlain- responsible for changes to the game

Other greats
Dr. J
Dominique Wilkins
"Pistol" Pete Maravich
Kareem Abdul-Jabbar
Isiah Thomas
Charles Barkley
Karl Malone
Bernard King
Sidney Moncrief
Walt Frazier
John Havlicek
Oscar Robertson