I think Bajor (before or after the occupation, of course) as it always sounded like a very nice and mostly temperate planet. The Bajorans generally seem like nice people on average too (religious quirks notwithstanding).
Of course, what very little we've seen of Romulus makes it seem like it'd be a nice planet too (far more than the scorching desert Vulcan is). But, of course, it blew up, so...