Coca-Cola and PepsiCo shares have been on different paths this year. Coke is up 15%, easily beating the S&P 500's 3.3% decline, while Pepsi is down 12%. That is counterintuitive because, while rivals, they are often lumped together.

Coca-Cola beat expectations on first-quarter earnings and revenue this past week. "Earnings season has given investors little to get excited about," says Kevin Grundy, senior research analyst at BNP Paribas Exane. "In contrast, Coca-Cola continues to hit on all cylinders and stands out fundamentally within the group." Coke shares are Grundy's top pick. The stock is trading at 25 times earnings expected for the next 12 months, making it only 15% more expensive than its peers in packaged food and beverages. Grundy thinks Coke can "trade at a wider premium."

Coca-Cola is primarily a soda company, though it also sells juice, milk, coffee, and tea. While Pepsi is best known for soft drinks, it has a big presence in snack food, from Lay's chips to Quaker oatmeal. Pepsi has been under pressure as consumers snack less or shift to healthier alternatives, says RBC Capital Markets analyst Nik Modi. Coca-Cola soda sales, meanwhile, haven't been affected much by recession fears and weight-management drugs.

The two also have different international exposure: The U.S. makes up 40% of Coca-Cola revenue, 60% for Pepsi. That means Pepsi is more at risk if U.S. consumer spending weakens.