That would be “March of the Penguins”. “Two months after its quiet launch amidst the big guns of summer, the penguins still roost firmly in the North American Top 10. Playing in more than 2,100 theatres in the U.S. and Canada, a reach usually achieved only by a Michael Moore documentary, the film is closing in on $50 million (U.S.) in domestic tickets sales, ranking it second to Moore’s Fahrenheit 9/11 as the most successful documentary in history.”