The Elder Scrolls IV: Oblivion

In keeping with the Elder Scrolls tradition, players will have the option to experience the main quest at their own pace, and there will be plenty of opportunities to explore the vast world and make your own way. Numerous factions can be joined, such as the thieves or mages guilds, and each contains its own complete storyline and the chance to rise to the head of the faction and reap further rewards.