What is the most hospitable environment? A tide pool? Also the most hospitable environment for genesis is likely different from the most hospitable environment for a complex ecosystem.
For life without photosynthesis, which takes a while to develop, some place with a lot of free chemical energy because the first replicators will be very inefficient. White and black smokers under the sea are usually put forward as candidates.
That's an additional good question that would complicate the simplistic model I suggested in my comment.