One of the country of Ireland's greatest exports of music is unquestionably the internationally successful rock band U2. Fronted by lead singer Bono and accompanied by guitarist/keyboardist/backing vocalist the Edge, bassist Adam Clayton, and drummer Larry Mullen Jr., the quartet has sought to continually push and redefine the anthemic quality of their sound since debuting in 1980 with the album Boy. While not all of U2's ambitious ideas have proven to be successful over the years, their decades-long career hasn't lacked for highlights when it comes to the group's output of albums.