I've been thinking, recently, of an RP plotline taking place 30 years after the Oblivion Crisis and the fall of the Cyrodiilic Empire.
For 30 years, the successor states have squabbled and fought with each other, tearing the former Empire to pieces and laying waste to the land with the scourge of war. In northwestern Cyrodiil, the Elder Council and their few remaining Legions are holding their ground in Chorrol, trying to keep the last fragment of the old Empire together, while a Nordish army lays siege to Chorrol. To the West, the Bretons make war with an Redguard-Orcish alliance. In the southern jungles and forests, the Khajit and Argonians flee deeper into the wilderness, as armies of Dunmer and Altmer clash, while the Bosmer hire out their services to either side as mercenaries. It seems that the glory days of Tamriel are at an end, and with rumours of an invasion from Akavir imminent, it looks like it might be for good. However, there is one new factor: A cousin of the Septims has gained the loyalty of a few veteran Legions, and controls the Imperial City, now almost a ruin after three decades of sieges and sacks. His family name was in fact Konenion, but he has taken the name Septim to give himself legitimacy. His name is Alexius Septim, and he has declared that he will restore the Empire in its entirety, and then and only then will he sit on the Throne and proclaim himself Emperor.
So that's the general idea. I'd roleplay as Alexius, whether I succeed or fail in my attempted restoration of the Empire depends on the actions of the other players, who RP as the other leaders of the races in this Civil War, and how I react to them. Of course, my plot makes it sound like Alexius is 'the main character' of sorts, and that simply isn't so, all the other characters that you guys will think up will be equally important to what happens to Tamriel in our little RP. But I don't know what your other characters will be doing, so I could only speak for Alexius' goal in my plot summary. And of course, if you don't want to be a big important leader, you could RP as any other Tamrielian that you choose. You could be Helseth's barber if you so choose, or a foot soldier in Alexius' army, or a Telvanni Wizard-lord profoundly uninterested in the whole affair, or any of the many other variations. TES has, after all, always been about the freedom.
Anyways, what do you guys think?