The Mexican fast-food restaurant may lag behind McDonald’s in terms of total sales and annual revenue, but it leads the industry in innovation. Taco Bell has embraced its unconventional cuisine, adopting the motto “Think outside the bun” by introducing a series of new and sometimes controversial foods. While some have been flops, the restaurant has also created a number of popular items, including Doritos Loco Tacos, which have a shell made from Doritos chips. Taco Bell introduced breakfast in 2014, quickly cutting into McDonald’s total morning sales, which once topped $35 billion.