Hmm, I think I'd live in Olivine city. It's a harbor city, so it'd provide easy travel to Kanto, as well as the nearby Cianwood City, so getting to the Safari Zone would be no problem at, which would allow easy access to exotic Pokemon :D There's also the Johto Battle Frontier right to the west of Olivine, which would give me an easy way to go and test my skills, if I'd either already completed my journey, or just had no intention of gathering badges :p The only downside is, that without Fly, there's a long way to get around the region, rather than if you lived in a central place like Goldenrod or something, but Johto is a small region after all, and I've got my Pidgey either way ;D