Coldplay was the best-selling band in the world in 2005, selling 8 million copies of its “X&Y” album, EMI’s Parlophone said Friday.It topped the list in both CD format and in digital form. Other albums in the top 10, which was compiled by music industry trade body IFPI, were Mariah Carey’s “Emancipation of Mimi” at No. 2, 50 Cent’s “The Massacre” at No. 3 and albums by Black Eyed Peas, Green Day, Madonna, Kelly Clarkson, Eminem, James Blunt and Robbie Williams. The figures show a further slide in the sales of albums. Norah Jones’ “Come Away With Me” topped the list in 2003 with sales north of 10 million.