People seriously love their cola cans. Yet Coca-Cola and Pepsi are always tinkering with their packaging. The two regularly funnel marketing dollars into limited-run editions, and occasionally spend eye-popping sums on overhauling their brands. Beverage consultant Jorge Olson says they’re lucky to be able to play with its packaging this way: “It’s a luxury because it is expensive to change cans. . . . It’s almost impossible for anyone else.” So why risk messing up a good thing? “Those brands need to do it to keep fresh because there’s such clutter at the shelf,” says Allen Adamson, managing director at branding firm Landor. “The balancing act is how to make sure it always feels authentic.” Adweek has compiled a few examples of the soda giants’ various looks from recent years. Decide for yourself how they did.