5. Crosby, Stills, Nash and Young
Key Members: David Crosby (The Byrds), Graham Nash (The Hollies), Stephen Stills (Buffalo Springfield) and Neil Young (Buffalo Springfield)
Signature Songs: "Ohio," "Teach Your Children," "Carry On" and "Deja Vu"
Current Status: They survived prison, hard drugs, never-ending personality clashes and a lousy 1980s reunion record, but they they broke up in 2015 because David Crosby couldn't help himself from talking smack about Neil Young's girlfriend, Daryl Hannah, and Graham Nash's new girlfriend, Amy Grantham. They're just three years away from their 50th anniversary, however, and a big money offer for a reunion tour may well make them put their issues to the side. Time will tell.