You're ultimate! Did you get the name from Might & Magic? How many hours does it take to complete...

1. Main quest
2. Exploring world/Beat all random dungeons
3. Each guild/faction
4. Arena
5. All quests
6. Knights of the Nine
7. The Shivering Isles

If you complete everything including Knights of the Nine and The Shivering Isles, can you get 450 hours of gameplay time?

DirectSong
Everybody go there please and listen to the soundtrack

Viddler.com - Let's Play The Elder Scrolls IV: Oblivion 01 - Prison - Uploaded by L0rdVega
Everybody go there and watch the video walkthroughs of the main quest with funny commentary, it's great!