My favourite is Staunton island sunce I can find better cars there. I also like it because it has better facilities. They are 2 Subways, a large park to go exploring in, a building you can climb (AMCO), 2 bridges, the university (Liberty Campus) and The stadium.
My least favourite is Shoreside, its just crap. I hate it since one road connects the Island, The Airport is harder to get to from the main area of Shoreside vale. The porter tunnel is the only thing what can get you to the airport quicker. It is too small. It has lack of roads.