On the surface, CVS Caremark (NYSE:CVS) and Walgreen (NASDAQ:WBA) seem pretty similar. But dig deeper, and you see some big differences: CVS has a huge pharmacy benefit management (PBM) segment and has played more aggressively in retail clinics, while Walgreen's agreement with Alliance Boots (and potential buyout of the company next year) provides it with intriguing overseas growth opportunities. 

In the video below, from Where The Money Is, the Motley Fool's investment show, health care analysts Michael Douglass and David Williamson consider the best stock.