Outkast and Fugees
Outkast are technically on some sort of indefinite hiatus, but with every year that goes by without a new album or tour, it looks more and more like they're over. The Fugees, meanwhile, are definitely broken up. They hate each other. While these two situations differ in many ways, they have one crucial thing in common: both of these beloved hip-hop acts have huge fan bases that miss them like hell. Just imagine how awesome it would be if they joined forces for a massive arena tour together – like the Nineties hip-hop equivalent of those Billy Joel-Elton John tours a few years ago.
It's hard to see Lauryn Hill eagerly signing on for this, but with the IRS on her case, some quick, easy money might not look so bad. And while André 3000 is pretty focused on his movie career right now, he could always change his mind. We can safely say that Pras, Wyclef and Big Boi would all do this tour tomorrow. Now we just have to wait for the other two to come around. (It's probably going to be a while.)