Ah, The Joshua Tree, the 1987 album that made U2 into megastars. The album that birthed "Where the Streets Have No Name," "With Or Without You" and "I Still Haven't Found What I'm Looking For." The album that helped turn Bono into the international activist that he is today. Named after a type of tree that grows in the American Southwest, The Joshua Tree has sold over 25 million copies, making it one of the top-selling albums of all time. That's pretty awesome.