obviously ill be using open cities
weapons and armor rebalance (ill make that one myself since im picky)
hunger/thirst/sleep mod
crossbows, spears, grenades etc
sailable boats
space cheese (completes mainquest for you after you have done it a million times)
somewhat goes with weapon rebalance but ill probably double damage across the board so that my character and mobs die in a few hits
much deadlier poisons and diseases
using GCD (morrowind) and nGCD (oblivion) were absolutely essential but it looks like i wont have to worry about that with skyrims perk system. i guess im one of the few people who hated the default 5x levelling system. im glad to see it go.
completely unlevel the game so that you have no idea what you will find..............it kind of already sounds like you can run into a cave and it will lock itself into a higher level than your character so this one im not to worried about. after playing oblivion with TIE though its hard to play level scaled games.
edit: cant believe i forgot hi rez textures....