For me the little things that make Skyrim an awesome one of a kind experiance are-
1. The way items, furniture, books etc are placed in the world to give an emotional response when one is in a certain mood. A few times i've come across a lone chair by the corner in some dank dark deep dungeon which gave me anything from a creepy ambience to a sense of loneliness or reminding me of a art painting in some museam.
2. Seeing how reactive the wildlife is with one another. Today i decided to go deer hunting for the very first time since getting Skyrim in november. After nearly finishing off a deer with a few arrows it suddenly turned and ran in my direction. At first i thought that makes no sense to run towards something that is trying to kill you. Then after finishing off the deer with an arrow i suddenly saw what made it turn and run my way. It was a vicious little Skeever it had bumped into while trying to get away from me which was now acttacking me ha ha. I also found out how great sneaking is during this hunting expedition.
3. How everything in the environment blends in without screaming "Here we are! Come get us!". Walking by some iron ore and not noticing it right away even in mines is great and makes things more believable without exerting any mental energy.
4. Chopping wood and other little job type opportunities where i can make some extra money to afford some room and board or a few health potions etc.
5. The intricate design of traps where even their construction and execution looks like one big puzzle in killing motion. Love the gasoline and igniteable lanterns.
6. The creepy chanting from Dragon walls.
7. Being able to catch insects and fish for food or alchemy.
8. The much more understandable enchanting and soul trapping that am actually doing on a regular basis now compared to Morrowind and Oblivion where i never did it because of my pea sized brain intellect

9. The way Dragons talk with a very evil inhuman all murdering voice.
10. The buetiful weather and stunning snow storms.
11. The look of roads and road signs.
12. Meeting travelers on the road from bards to strangers looking for direction or famous npcs from past Elder Scrolls chapters.
13. The look and effects of all the food and drink in the world. Actually has me eating and drinking on a regular basis eventhough the world of Skyrim doesnt demand it.
14. The much more useful spells and how they are separated into more logical schools.
15. How wolves howl as if to warn the player they are near and not to get any closer.
16. All the unseen wonders right in front of one yet not visible to the naked eye like underwater ship wrecks.
17. The clannish family manner of Orcs in their forts.
18. The multiple intricatcies of smithing where its just not a one step affair.