The Elder Scrolls IV: Oblivion® 

The Elder Scrolls IV: Oblivion Game of the Year Edition is a role-playing game in which you can unravel the main quest at your own pace or explore the vast world and find your own challenges. The Game of the Year edition includes the Knights of the Nine and the Shivering Isles expansion. You can create and play any character you can imagine, from the noble warrior to the sinister assassin to the wizened sorcerer.