Diet Coke Unseats Pepsi as America's Second Favorite Soda 7.72K Brian Moylan 03/17/11 03:59PM Filed to: rivalries rivalries Diet Coke Coca-Cola Pepsi sodas Obesity Gettypic Diet Coke's unseated Pepsi and is now America's second most popular soda, behind its fat daddy Coca-Cola. Looks like Coke officially wins the Cola Wars. Remember, America: Just because you're drinking diet soda doesn't mean you're not a fat fuck.