I thought of this idea, what if there were a thread where people collected pics of places they hope will be included as properties in the future? Here are some places I found while exploring that I wouldn't mind the ability to own.
Simple 2 car garage beach house
A higher end beach house that could easily be made to have a 10 car showroom on the bottom floor
A new type of high level apartment could be purchasable here. From this angle you would see out over the ocean. Obviously the interior would be special because one side would be rounded. Could you imagine the view from the round room? It even has a long driveway leading to a garage out back. Could be a new 20 car apt with prices upward of 500k.
This house out by the prison could work, just make the barn a garage.
A hotel room would be cool and a cheaper alternative for lower level players. It would be cool if Rockstar worked in parking spaces like in GTA IV, but unfortunately that really wouldn't work online.
So go out and explore San Andreas! Post your dream properties!