Journalism. Want to write your own book? I sure do without mods. Especially since I'm on Xbox.
Swampy places...I don't want "oh a few puddles some ugly trees," I want mostly water, bubbles here and there, maybe get stuck in swamp gunck, small islands only room enough for a tree, and what a NORMAL swamp would be like.
Vendors, too. Someone mentioned that, and I agree.
Footsteps, like for tracking animals or...people! :blink:
More cities and settlements. Forts like in Morrowind, abandoned houses here and there, and of course, some way to claim an interior? Like if the current owner dies, then the house can be used by you? All the chests DON'T respawn, nothing is red, so you can take over it for Rps mayhaps? Oh, and some settlements in the trees? (A must for Valenwood)
Stores, like carpenter, or stores that sell oddities, (Like the items in the Museum of Odditties in SI)
More artifacts. Not just quest-related ones, but like random ones scattered. Maybe a powerful ring that you might read about in books? More books relating to subjects.
More drinks. I don't think EVERYONE drank wine, ale, beer, and such back then. Maybe fruit juice? WATER!!!!!!!!!
More strange food. Like creature eggs.
unique creatures. Morrowind had Nix Hounds and the ever so famous Cliff Racer. Oblivion...has what... boring mythical creatures most people have read about. (Ogres, trolls, goblins, etc)
The random scattered caves and ruins? Uhh? Add more design! In Morrowind there was daedric architecture, Dwemer, and human architecture! Make some new ones too!
Weather has an impact! Blizzards make you suffer cold damage unless you are resistant to frost, or are wearing fur armor. Rain makes it easier to be shneaky! :toughninja: Storms can maybe....just MAYBE strike you with lightning in a very large plain, and you're the highest object.
Weaponry. Crossbows...spears, halberds, and all that junk. Skills are seperated. Short Blade, long Blade, Axe, Blunt Weapons, etc.
Effects! Like levitation (Although the city problem...), or blind! Stuff from Morrowind.
EDIT: As the above poster said, wounds wounds wounds!! Be crippled like in Fallout 3, to add to the immersion