Star's seven Earth-sized worlds set record:
The interesting thing is that NASA is calling it habitable, but only by zone. There's no way to know if humans could live there (atmosphere composition, temperature, air pressure etc).
The cool thing I did learn though is that we would have to migrate to a place that had to be within the size of our Earth. Gravity is larger on larger planets, and although it would be ideal to have a larger place to live... water and life may not be able to flourish on a planet the size of Jupiter.
It's actually very important that they're around 1x g. Any planet with significantly higher gravity would probably drastically reduce life span as your heart has to work much harder to pump blood around your body.
Statistics like that make me wonder how we could provide a scientific manifesto of just how rare something like the Earth is/how hard it would be to find a new home.