Titan is the most earth like in the Sol system. Venus and Mars used to be but Venus was destroyed by global warming and the magnetosphere of Mars is nearly gone so has had its atmosphere stripped away over time. Leaving Titan the closest to earth like. Just really really cold. Like water is literally rock on Titan cold. Lol
In spite of any Musk propaganda none in our star system are actually viable, we don't have the technology to get to other star systems, and if we don't go extinct in the next century, we have hundreds of millions of years to sort this out, so no one could answer this question honestly
