Over the Christmas week, December 22nd through 29th, Angry Birds was downloaded 30 million times. On Christmas day alone the game chalked up over 8 million downloads in a 24 hours period. Angry Birds Star Wars holds the #1 position on the US iPhone charts since release.
Before their 3rd "BirdDay", as Rovio states on their site, they have release four critically-acclaimed games, developed two top rated Facebook games and have hit over a billion downloads. Two games have done particularly well, Angry Birds Star Wars and Bad Piggies" which have dominated app charts, with ABSW being at the number one position on the U.S. iPhone chart since it was released.
I included a cute little info-graphic that they made to show off their numbers.