FFVII is the easy answer here. Hell, FFVII probably has the best opening hours of the game, which extends easily as far as Midgar (and arguably even beyond). Despite my very strong criticism of much of the rest of the game, I consider the first disc of FFVII overall to be one of the best gameplay experiences in the series (and of all JRPGs). Of course, the farther you get from Midgar, the worse it gets.