6. Elder Scrolls IV: Oblivion (PC with expansions & mods, also on 360 & PS3)
The elder scrolls games have always offered immense freedom and player choice, and Oblivion was no different. However, they also had their share of problems and the storytelling aspects weren't always as strong as perhaps they should have been. Oblivion's storytelling improved greatly upon those found in Morrowind but also added elements to make the game more immersive. Voice acting helped to bring you into the world, especially in the main quest with Patrick Stewart and Sean Bean voicing two of the main characters. No longer did you attack something without hitting it; gone was the background die roll. Attacks were now based upon your own skill rather than purely based on stats. Mini-games meant a mixture of skill as well as statistics contributed to aspects like lockpicking. And the guild quest-lines each had their own fully developed storylines that felt as if they belonged in their own separate game.
The content of Elder scrolls games is always massive and Oblivion didn't disappoint, but it also avoided much of the problems of generic tasks that open world games typically have. It incorporated some brilliant quests with ingenious and genuinely interesting tasks. This is the main reason Oblivion is ahead of Skyrim in my list as it's an area where Skyrim was relatively weak. Even though Skyrim is superior in most other ways, the amount of fun and immersion I had in the Oblivion quests meant that Oblivion won out.
One of my favourites was the dark brotherhood quest which tasks you to kill five people in a locked mansion without the others knowing. Each one becomes more paranoid or scared and each has their own suspicions as to the murderer's identity... whispering their thoughts to you as you kill them off! The fighters guild quest tasks you go undercover to find out the secret behind the rival guild. The main-line quest where you witness the destruction of Kvatch and has you entering your first Oblivion gate. The storylines (Main and guilds) were all engaging and interesting. The Mages guild had a lengthy tale concerning necromancy whilst the thieves guild had you discovering the true identity of the infamous Gray Fox. Even the one-off quest lines helped add to the sense that this was a vibrant and living world.
However, for me, the quality described above is only half the story. The expansions, DLC, mods and the ingenuity of the modding community are what really boost this game up to sixth place. Officially, the Shivering Isles added a more vibrant and bizarre world more in line with Morrowind than traditional fantasy whilst the Kinghts of the Nine DLC added an opposite quest line to the Dark Brotherhood. Unofficially the OOO mod, Kumiko manor, the Archaeology guild and saddle-bags (among many others) all added great content to an already brilliant game.
