In less than a decade, T-Mobile transformed from the sparkle in a CEO's eye into one of the largest wireless carriers in the U.S. The company—known for its vibrant pink logo and the charismatic celebrities who've filled its ads—takes pride in pioneering new cell-phone trends. Their newfangled 4G network sprawls across 217 markets to reach 200 million people, making it one of the most sprawling networks in the United States. Chatters access this invisible web via contract-free plans, which release them from the boot heel of years-long agreements enforced by most cell phone providers. The company's modern cell phones are lightweight, multi-functional, and double as secret explosive devices while you pretend to be an international spy. Despite its success, the company remains dedicated to its principles, earning a spot on the Ethisphere Institute's list of world's most ethical companies for three years in a row.