It was the biggest tease in rock history. For a single night in December of 2007, Robert Plant and the rest of Led Zeppelin did a glorious, smoking two-hour set at London's 02 Arena. Jimmy Page, John Paul Jones, Jason Bonham and most everybody else on the planet was dying for the group to tour. They could have made a ton of cash, but Robert Plant stood his ground and refused to do it. Fans may shake their heads in frustration over the choice, but you have to respect the man for sticking to his guns.