5. Megadeth

“Wait, when did Megadeth break up?,” some of you may be asking yourself. While it didn’t last long, Dave Mustaine officially disbanded Megadeth in April of 2002 after getting diagnosed with radial neuropathy (aka, major nerve damage to his left arm). Following a year of recovery and therapy, Mustaine gained enough strength to start work on a solo album. However, thanks to contract obligations to its European label EMI, Mustaine was forced to release what would become 2004’s The System Has Failedunder the Megadeth moniker (even though it didn’t feature longtime bassist David Ellefson). The album and its tour was so successful, though, that Mustaine decided to keep Megadeth going (and Ellefson eventually rejoined the group). Still, Mustaine disbanding Megadeth was a surprise to many at the time.