I'm in.
My favorite campaign setting is called Mythica. It is a joint venture homebrew with buddies from high school and before. We don't get to play much, so the plot has been moving rather slowlly since the advent of 3.0.
The basic premise was to allow us to slowly expand the world as needed. We started out in the city of Thain, which had been occupied by invading orcs for a generation. Suddenly, and for no apparent reason, the evil sorcerer that was running the orcs was slain and the orcs abandoned the city. The prince took a contingent of nobles to follow the orcs. At the beginning of the campaign, the prince had not been heard from for weeks. Various factions were all attempting to gain some degree of control over the city. Examples included the remaining nobles, the ruling family (just the young princess and her controlling regent), the dwarves who ran the salt mines under the town, a couple of religious groups, etc.
Each PC was to be a representative of one of the factions, so everyone started out with common goals of helping the city regain it's footing after being destroyed and occupied by the orcs, as well as differing goals depending upon the faction they represented.
So after over 3 years of game time and real time, we actually managed to find the lost prince in our last session, in a distant land to the east, and are now attempting to return him to the city. He is the only remaining nobility, as the poor princess was turned into a hag in one of our failed adventures.
I don't have a favorite published setting, but am looking forward to Eberron.
