Regional bank operator People's United Financial Inc. said Monday that it agreed to buy Financial Federal Corp. for $738 million in a stock and cash deal.

Banks historically have been the best-performing stocks after a financial crisis. That’s right, even though the Western financial system teetered on the brink of collapse, Cramer still recommends buying these companies. But not all of them. In his newest book, "Getting Back to Even," he’s largely focused on just the strong, regional outfits in position to take share from their weaker rivals.