There's only one place in the entire universe that we know for sure supports life, and you're standing on it. We haven't been looking for long, though, and our ability to scope out other planets is still pretty limited. According to the Drake Equation, however, there's a good chance that we're not completely alone.
The problem is that we've been looking for solar systems like our own, and stars like our sun are not especially common. Planets like our planet orbiting them are even rarer. But maybe we shouldn't be looking for Earth-like planets. According to Laboratoire d'Astrophysique de Bordeaux astronomer Sean Raymond, we should be looking for eyeball planets instead.