The Elder Scrolls IV: Oblivion

Adds armor that you can purchase for your horse to protect it.

Collect all the "Crusader Relics" and help of the Knights of the Nine to destroy the evil Ayleid King Umaril.

Access to your own castle with staff including servants and guards.. This DLC is designed to provide equipment and a place to live for a fighter class character.

Makes the Wizard's tower available as a new house for the player. It contains many useful enhancements for the player. It is designed for use with magic characters

Adds a new quest to repair the Arcane University's Orrery.

Mehrune's Razor is an official plug-in that revolves around a quest to uncover the Daedric Prince of Destruction's dagger. It adds a new dungeon, items, weapons, and armor.

The Shivering Isles is a large expansion pack for Oblivion that takes place outside the main gameworld. The player travels to the Madgod Sheogorath's Realm, questing for the Daedric Prince and trying to stop the Greymarch. The Shivering Isles is roughly 1/4 of the size of Tamriel.

The plug-in adds spell tomes, which can be read to learn new spells. They will appear randomly in chests.

Adds Dunbarrow Cove, an abode which can be used as a player base. The den can be upgraded with a band of thieves and new equipment. It is designed for use with stealth characters