Rite Aid (RAD 24.00%), Walgreen & Co (WBA -1.33%), and CVS Corp (CVS -1.07%) are the largest pharmacy operators in the United States. The three are responsible for filling more than a third of the $276 billion worth of prescriptions ordered by doctors in 2012.
 
Since millions of Americans are newly insured under health care reform, spending on prescription drugs may climb as much as 9% this year, creating a massive opportunity for Rite Aid, Walgreen, and CVS to capture market share.  
 
In the following slideshow, you'll see which of these companies may have the best chance of capitalizing on this growth opportunity and rewarding investors with shareholder-friendly profit.