Attribute, skill, race and gender checks in dialogs.
Handcrafted dungeons and caves filled with secrets like secret rooms are areas you can access only by spells or use of physics and items.
Reputation system that will make your decisions influence the game world.
Game world filled with content, diverse geography,plant life and land marks so you can like in Morrowind find your way around even if you dont have quest compass or mini map.
More skills, weapons and armor types, maybe even guns in form of early muskets that would be quite devastating but imprecise and slow to reload.
Quests with multiple and non violent solution.
Main quest with several endings.
Customizable difficulty, while I enjoyed playing in hardcoe mode for FNV there were some things about it that I did not like, so having in options choices like how strong will be the enemy, how fast do you gain xp, need for water and food, it will allow players to make the game challenging as they want it to be.
Traits and perks, traits adds to making of unique character and perks feel like rewards for leveling, while they are not part of TES series I still think that adding them would be a great thing for the game, also adding a TES version of Vault boy.
This are few of my ides, sorry for bad english and if I should have posted this elsewhere and not making a new topic. But I would like to hear opinion of community.