For me
Kanto: Saffron or Celadon City. They're both large and I assume they'd have everything I'd need to live. Plus if I'm bored I can get to Johto quickly through the Magnet Train in Saffron.

Johto: Cianwood City. It's small and quiet. If I need to access the mainland I can just surf, or put on a bikini and swim.

Hoenn: Fortree City. I'd love to live in a tree house. Plus it's close to the wilderness.

Sinnoh: Canalave City. Near the ocean, a thing I like. Can get ferries to various places.

Unova: Nimbasa City. It's like a giant entertainment hub with stadiums and theme park rides. There's also a train station, so plenty of room for trips. Runner up is Undella Town due to being near the ocean.

Kalos: Lumiose City. It's huge, lots of things to do and places to see. Plus it's directly in the middle of Kalos, if I get bored of Lumiose, I can go somewhere else.

Alola: Hau'oli City. Somewhat large, near the ocean, has a big shopping mall.

Galar: Hulbury because food and ocean.

Hisui: Palkia's asshole

Paldea: Levincia because it's near the ocean, Iono is fucking hot and it just looks cool at night.