McDonald's (MCD -0.42%) has been a dud in 2012, while Yum! Brands (YUM -0.18%) has continued to outperform, but with that run has come a premium multiple. 

So which stock is a better buy today: the cheaper, underperforming McDonald's or the rosier and more expensive Yum! Brands?

Mickey D's has a more sustainable long-term model than just about any company in this space, and has a low price-to-earnings ratio right now. In a world of short-termism, it's easy to forget that the best investment is measured in years, not quarters, and when you take a look at McDonald's long-term trend, investors are getting a bargain, making McDonald's the better buy today.