Perhaps the most unexpected comeback to be featured in this list is that of former-ABBA Goddess, Agnetha Fältskog. Fältskog's solo releases have been sporadic with the singer usually remaining tight-lipped about her upcoming work. To the delight of ABBA fans, Fältskog's manager confirmed that the singer is in the process of recording a new English album with Jörgen Elofsson (the man behind many solid Westlife and Britney Spears hits). Rumours also imply that the singer has recorded a duet with Gary Barlow, which could potentially bring some mainstream publicity and interest to the album. Surely if Agnetha from ABBA cannot save the pop world, then no one can.