The Thalmor, Assassination of the emperor, The Dumer getting their homeland [censored] by nature and Argonians, and the Empire crumbling. There are more, but I just can't think of them.
Usually games fall flat and end up svcking ass, such as Fable, when they go and try to progress the story, but surprisingly TES done it well I feel. Maybe it's because of the stasis of technology in the universe. Bethesda know people want the Elder Scrolls to be a fantasy game, and I don't see them changing it any time soon.
The most Technologically advanced race were the Dwemer, and even they were well written and interesting.
But mainly, TES games have a good progression I feel.