9. The Spice Girls
You might be thinking: "Wait, his has totally happened before", and you would be right. The Spice Girls have reformed before - twice, in fact - but it would only be fair if they could do it one more time to put an end to 'girl power' once and for all (before they past their sell by date for good). The Spice Girls are without a doubt the biggest female pop group the UK has ever produced, and as a result would easily sell out stadiums and arenas worldwide - as was the case with Take That. The hype behind them would back this up, following their brief reunion at the London 2012 Olympic Games closing ceremony. It's hard to believe that it's been 13 years since they first split up, but following the somewhat successful West End musical 'Viva Forever', there will always be a demand for girl power and they should seriously think about embarking on one last reunion tour for the good of mankind.