Wii

from the Infendo page - one of the video world's catchiest phrases

Think about it: Before this campaign, people mocked the Wii’s name. Fans thought Nintendo execs had lost their minds. Then came five simple, clever, friendly words, “Wii Would Like To Play.” BING. Suddenly the world “Got it” and understood what Wii was about. The little machine’s name got mocked no more (well, not as much). People who hadn’t bought a console in years wanted one. I’d seriously call this the most successful video game ad campaign of all time.