Kanto: Cinnabar! It'd have to be the Gen I Cinnabar though obviously xD I love the idea of living on a small island like that and all the Poison types in the mansion would make for wonderful friends, plus having the Seafoam Islands nearby would be sweet n.n
Johto: Ecruteak. Once again, kinda just for the Pokémon in the tower haha, plus it's a very beautiful city and having access to Bell Tower would be pretty epic. Also there's entertainment from the dancing geisha so you'll never get bored :3
Hoenn: Lilycove. The beachy-harboury atmosphere is great, the caves would be fun to explore, the department store would be very useful and lighthouses are awesome! Plus there's loads of interesting Pokémon just outside the city so they'd be awesome to play with.
Sinnoh: Snowpoint! There's no other choice for me, I absolutely love Snowpoint. The snow, the atmosphere, the gym leader, the surrounding mountains and forests, the ancient temple, it'd just be such a nice place to live. I'd be so glad to live there.
Unova: Icirrus City I guess for similar reasons to Snowpoint, but that wouldn't be all year round :( There's not really many places in Unova that I do like, so I guess that's the best option haha.