Earth is the only planet we know to this day that has life on it. To this day, we have found planets in Habitable zones and planets that once had rivers on them but no planet as complex as planet earth. Earth has flowing water, protective atmosphere and much more to be able to host life forms.
Trappist-1 is the best hope we have for life outside out earth so far. Trappist-1 is a exoplanet system outside of the Milky way. In this Exoplanet system, every planet is earth sized. Many of those planets are in habitual zones and that is a recipe for Alien life. The only problem is that "they orbit in extremely tight circles around their star, compared to the planets in our solar system. Scientists have determined that the six inner planets are in what’s known as orbital resonance" (Sarah Pruitt,3)
Earth vs. Earth like Planets