Exoplanet 55 Cancri e is not habitable; for starters, it's much too hot, with a temperature of 3,900 degrees, and its 18-hour year would likely mess with our heads anyway. But if we could live there, we would be rolling in it, because 55 Cancri e appears to be essentially a 26-septillion-pound chunk of diamond.
Well, there's some graphite in there too -- all told, only a third of the planet's mass is likely diamond. But that's still a quantity of diamond three times Earth's mass, i.e. enough to give Marilyn Monroe several consecutive heart attacks. We're talking about an engagement ring even Kim Kardashian wouldn't wear.