Rite Aid (RAD -51.21%) and Walgreen (WBA -1.18%) are two of the biggest pharmacy operators in the nation, and both companies just reported first-quarter earnings that appeared to disappoint investors.

However, with baby boomers turning 65 at a pace of 10,000 per day, and millions of new customers thanks to health care reform, investors are right to wonder whether Rite Aid or Walgreen is the better buy.

In the following slideshow, I'll compare the two and share with you my thoughts on what may be in store for both companies.