4. Backstreet Boys
In 2011, the boys of Backstreet got back together to hit the road with NKOTB. However, it wasn’t quite the same without Kevin Richardson. But earlier last year, the group announced that he and the entire line up were getting back together again. Over the summer, the group embarked on world tour to celebrate their 20th(!) anniversary, which also included promotional stops on Good Morning America and the Hollywood Walk of Fame.