I would like to live in Fuschia City, in the house next to the Safari Park warden with the gold teeth, where the fisherman who gives you the good rod is. I think I'd be able to buy it off him because he has two brothers living nearby, and he'd probably get depressed living in Fuschia because no-one would visit him knowing that his brother is giving away free super rods just along the next route.
It has a nice pond in the back garden for my Pokemon to play in, and I'd be able to get a dream job working in the Safari Zone. I'd have a Drowzee that could play with the other Drowzee and Hypno in the Fuschia Gym, and that would be a good way to get to know the gym leader Janine, who, judging by the costumes and invisible walls, is into some kinky stuff.
I'd also have a Psyduck and a Slowpoke, who could play in the pond, and I'd find a Munchlax egg from one of the Snorlax while I'm out exploring. Fuschia is in a great location because it's got a direct cycling route to Celadon, which I also love. I would get good exercise cycling uphill on the way there, and then come back downhill with all my heavy shopping bags and casino prizes on the way back. It's also near the beach, and it's a very popular swimming spot so it must be great weather.
Well if I was a trainer, I'd probably be more mobile, traveling the world with my Pokemon. But it would be nice to live in one of the Castlelia complexes or maybe in a island town like Humilau or Pacifidlog. I'd battle for money haha, that's a good job.