I love Bastok. It has the best start area, in my opinion. It's very clearly laid out in terms of where the next tier of mobs appear (bats and bees, then the section with birds, lizards, quadav, and saplings, then move to the Fumaroles with crabs and bees, then hike over to Konschtat for the worms and bees). I've leveled jobs in all zones, and Gustaburg, while being extremely ugly, is the fastest to level in.. from my experience.
You also get the quick Altepa > Korroloka > escape > Bastok trick. The mog houses are also a lot closer to the chocobo stables and auction houses. It's just quicker to navigate in general.