• Forward P/E: 7.6
• 2014 stock performance: -15%

It's only fitting that the No. 2 cheapest stock on this list is also a refiner: Marathon Petroleum (MPC).

Like Valero, Marathon has been devalued by concern about the export move and the refining industry more broadly.

But Citigroup recently upgraded Marathon to "buy" from "neutral," arguing the market "underappreciates" the company's earnings power following a string of acquisitions, stock buybacks and other moves.

Citi's not alone as 73% of analysts who track Marathon have a "buy" rating on it. The stock is trading a whopping 25% below Wall Street's average price target of $104.62.

NEXT: General Motors