A few of the recent pieces I've liked:
Maryn McKenna at Superbug: Terror and Bioterror: 9/11 to 10/4 (This is the first in a series on the bioterrorism fears - some of which were realized - that followed the 9/11 attacks.)
Mark Magnier, Los Angeles Times: India's night rat killers: Hunting shadows that scurry
Scicurious at The Scicurious Brain: Can probiotic yogurt cure your psychiatric ills?
Matt Chaban at the New York Observer: Janette Sadik-Khan Is the Best Mechanic the City Streets Have Had in a Generation--So Why Do Motorists Hate Her So Much?
Charles Ornstein, Tracy Weber, and Dan Nguyen at ProPublica: Piercing the Veil, More Drug Companies Reveal Payments to Doctors