>>47513306In terms of pokemon availability, Kanto
In terms of a structured experience with ascending difficulty when fighting enemy trainers, Johto
In terms of where to realistically live, Eastern Hoenn. A treehouse city is cool until you realize the poor insulation and potential pests invading your home. Further east you get to lived sandwiched between a mountain of graves and a Team Aqua base full of assholes who try to steal your pokemon, and even further east you are stranded on an island that you need to Surf/Dive/Fly out of. Everyone living in Pacifidlog town would be caked in sea salt at all times.
In terms of actually having traverse it, Sinnoh
In terms of getting past artificial roadblocks, Kalos in theory because the roadblocks are lazy excuses and Sinnoh in practice because you have to backtrack to random places without warning.
In terms of gameplay experience, Kalos because it's piss easy, the third gym leader hands you a Mega Lucario who can sweep the entire game. Even if you don't use it, (or exp share) all the enemy trainers are underleveled and generally non-threatening.