I wish you could join the guard in skyrim and do quests to rank up and eventually become captain of the guard. It would be cool to go war with other cities guard (maybe over resources, the winner gets more supplies for their shops which makes lower prices). I like the idea of fighting with others on your team in the same situation as you are instead of being the only one trying to save the world all the time. I know there is some quest in oblivion where you can become the jail guard for like a day or something to gain access to the jail to complete another quest, something like this could be the first quest for when you join the guard in skyrim. Like after joining the guard you have to patrol the jail for a day, then your next quest is to patrol the streets for a day. Then maybe the town will be attacked by a dragon and you have to fight with your fellow guards to fend it off, and eventually battle other cities for economic benefits and such. Eventually becoming captain of the guard and gaining power to declare a war on a town to take their resources.
I heard there is a city that is primarily a dunmer city, so it would be cool to have a bunch of dunmer go up against the nords. Or have a city of imperials go up against a bunch of orcs. I would join the dunmer army because im 99% sure im going to be playing as a dunmer.
I highly doubt something like this will happen in skyrim but it is my dream. Others have talked about an imperial legion faction or something which would be awesome, or if you could become a guard somehow, even if its just for a few quest you need to complete for the count (Jarl i guess it is in skyrim) then i would be very happy.