Modern Warfare 2 had the biggest first-day sales presence in the entire entertainment industry. Sure, its $401 million launch day revenue topped literally every other piece of entertainment media ever released, but in terms of units sold, it was surpassed by the Harry Potter and the Deathly Hallows book and ticket sales for The Dark Knight.
However, in an attempt to clear up any obscurity, the Guinness Book of World Records proclaimed that the game had the "Most Successful Entertainment Launch of All-Time." Though we shudder to think that we live in a world where success is measured in the amount of money earned, and not the number of lives a book, movie or game touches, we suppose congratulations are in order. So, congratulations, Modern Warfare 2! Guinness says you did it.