At this point, Madonna is not unlike Brett Favre. In many ways, she has run out of things to accomplish, yet there's still potential for her to be at her peak all the time. (They're not exactly the same, though — Madonna certainly throws fewer interceptions and probably hasn't spent much time in deer stands.) But she does dominate the numbers. Case in point: She holds the record for the most successful solo tour in history, and on this day in 2008, the "Sticky and Sweet" trek kicked off.
Named thematically to coincide with her album Hard Candy, the "Sticky and Sweet" tour was a massive undertaking that seemed to go on forever. Madonna was absolutely at her peak, as she tore through most of her classics as well as the choice cuts from her more recent work. And of course there were plenty of costume changes, special effects and her totally reasonable guitar playing. Madonna sold most every ticket made available, and she played in front of 3.5 million fans in 32 different countries. All told, she brought in $408 million, which earned the "Sticky and Sweet" tour the top position in the list of the biggest solo tours ever (in typical Madonna fashion, she displaced herself on the top of that list).
The tour ended up being a great showcase for the Hard Candy songs, which are excellent and are among the best of her 21st century work. Madonna has managed to make just about any piece of music her own, as she did with "4 Minutes."