Best: NL East - With 3 teams within 4 games of first place and all 3 teams are at least 10 games over .500. This division has a shot of landing 3 teams in the playoffs when the season is over.
Worst: NL North - This could be a barn-burner of mediocrity and awfulness. 4 teams. 5 games separate them. Unfortunately the division leader is 30-31. It’s looking more and more like 80 games could win this division.
Best: AL West - Scottsdale could run away with this division, but the rest of the teams are still within a multi game winning streak of making this into an interesting division race.
Worst: AL South - There was no clear-cut winner so I just went with the division whose bottom teams were worse than the other divisions’ bottom two.
* You could make a case for any division in the American League for both classifications. In each division (minus the South) the second place team is 5.0 games out. It's early, but that's quite a ways out of first place.