9. The Police
When you think about bands falling apart, it's normally over the members no longer being able to work with each other. For as much money that you might be leaving on the table, it might not be worth it if you have to deal with the same BS excuses from your band members day in and day out. Then again, sometimes deciding to call it a day is just about being realistic.
That's not to say that the ending of the Police wasn't at least a little bit tense. As time went on, Sting seemed to be taking greater control over every aspect of the music, with songs that felt like they were more suited for what he would eventually do in his solo projects. By the time they reached Synchronicity though, they were still a unit and were now considered one of the biggest bands of all time, packing out stadiums around the world.
Though most bands would try to soak up the moment for all it was worth, this was around the time when the guys really had said all they wanted to say as a band. While they still had the chops to work together, they were thinking about branching out into their own projects, with the added plus of not trying to outdo themselves from the masterpiece they just made. Granted, if you've reached the stadium level that's normally reserved for acts like the Beatles, it might be best to quit while you're ahead.