Since June 1st, the Rockies have the best record in the division. 21-30.
Yes, that is 21 wins and 30 losses.
Looking at it in perspective, the teams that would be winning the NL West right now, based on record, are:
White Sox
Cardinals
Angels
Braves
Red Sox
A's
Yankees
Nationals
Astros
Twins
Indians
Marlins
Blue Jays
Phillies
Cubs
Mets
Rangers
Orioles
(Tigers are .5 games back, Brewers are 1.5 games back)
So there you have it...out of the 25 other teams in MLB, 18 would be leading, 2 would be within 1.5. I have run out of words to describe the National League West...a pitifully atrociously disaster doesn't do it justice.