Ok, well just recently I beat Elder Scrolls IV: Oblivion and the x-pack for it, The Shivering Isles. After beating it, i figured out a cool idea for a server.
Ok, you take Zangarmarsh (Because it looks like Sheogorath's Realm slightly) and erase all mobs in it. Then, you spawn a castle or something being Sheogorath's castle. Then, you make quests like you find there, make dongions like there, and make items similar to oblivion's.
Also, you could make a custom class maker that makes it so you make your own class basicly, and make it so you can learn from any class trainer like oblivion is like.