One of the best features that one can find in TESV: Skyrim, is large variety of stories and events that are taking place all over its land. There are countless number of adventures that one can get involved in. These are the main ones:
Civil War
Skyrim is set 200 years after the events of Oblivion, though it is not a direct sequel. The game takes place in the land of Skyrim, a province of the Empire on the continent of Tamriel, amid a civil war between two factions:
The Stormcloaks, led by Jarl Ulfric Stormcloak, are made up of Skyrim's native Nord race. Their goal is an independent Skyrim free from Imperial interference. The Imperial Legion, the military of the Empire, opposes the Stormcloaks and seek to reunite and pacify the province. General Tullius leads the Imperial forces in Skyrim.
Alduin
Alduin was the first dragon among many that ruled over men and mer. The dragons viewed humanity as a lesser species, and kept a tyrannical hold on mankind, but soon, in an event known as The Dragon War, men stood up to their dragon overlords.
Now, in the Fourth Era, he has returned to claim what he believes to be rightfully his and fulfill his destiny as the World-Eater.
Dragonborn
Dragonborn scarcely exist, and it is rare for more than one to appear within an era. They can belong to any race or gender, since the Dragon blood is a "gift" bestowed to certain mortals favored by Akatosh.
Some Dragonborn individuals have knowledge of the Thu'um, and can consume a slain Dragon's soul and absorb its knowledge, allowing them to learn Words of Power quickly. It is said that the Blades have always guided, protected, and served the Dragonborn, whom they consider "The ultimate Dragon slayer".