Just for Black History Month - here's some curated lists of the "Five Greatest" in several categories. Feel free to disagree...

Five Greatest NBA players
1. Julius Erving
2. Wilt Chamberlain
3. Michael Jordan
4. Bill Russell
5. Kareem Abdul Jabbar


Five Greatest NFL players
1. Reggie White
2. Barry Sanders
3. Jim Brown
4. Walter Payton
5. Lawrence Taylor


Five Greatest MLBaseball players
1. Willie Mays
2. Jackie Robinson
3. Hank Aaron
4. Bob Gibson
5. Joe Morgan


Five Greatest Boxers
1. Muhammad Ali
2. Sugar Ray Leonard
3. Sugar Ray Robinson
4. Joe Louis
5. Jack Johnson


Three Greatest Martial Artists
1. Michael Jai White
2. Jim Kelly
3. Kareem Abdul Jabbar


Five Greatest Scientists
1. Frederick Douglass
2. George Washington Carver
3. Gladys West
4. Neil deGrasse Tyson
5. Ben Carson


Five Greatest Actors
1. Denzel Washington
2. Sidney Poitier
3. Cicely Tyson
4. Morgan Freeman
5. Don Cheadle


Five Greatest Comedians
1. Eddie Murphy
2. Richard Prior
3. Cleavon Little
4. Kevin Hart
5. Kareem Abdul Jabbar (as Roger Murdock)