Guild Towns- For the guilds that have been around a long time, they will be able to outline what they want as their town and then it would be implemented, it could have its own NPC's and stuff, and maybe possible for people to give items to an NPC or put it in a "Guild Chest" so that other members of the guild can get the item if needed.
Player-Owned Houses- For those who have been around a long time, and have the money to afford their own home.