Elder Scrolls IV: Oblivion
This was just a groundbreaking game. I know the graphics aren't as nice as Skyrim, but the world has more depth and the guilds are all full games in themselves.
Such a big open world, fully populated with flora and mystical fauna (Minotaurs and unicorns), an endless supply of side-quests.
Oblivion destroys Skyrim in the following places:
- Much more interesting and in-depth Thieves Guild, Assassin's Guild, Fighter's Guild, and Mage's Guild.
- Being a vampire is infinitely better than being a goddamn werewolf
- Skyrim leans too heavily for the Nord race, while Oblivion's story leaves race selection more open-ended. I always want to be an Argonian but it felt weird to be an Argonian in Skyrim.