10. 'Return of the Stingray Guitar'
U2 have written an absurd amount of songs over the past five years that virtually nobody has heard. They briefly decided to let the public in on some new tracks when the 360 Tour hit Europe and South America in 2010. Many nights opened with "Return of the Singray Guitar," a monster riff of a song that kicks ass even though it never really sounded finished. It was a sign to the fans that the band was moving forward, even though it's likely nobody will hear hear this one again. Too bad.