Well I have a mod installed that makes my character walk faster than the vanilla speed because the default speed is a little bit too slow. But then again I love walking in real life, I often go out for a walk and think about life. They say you have the greatest ideas during walks.

It may sound strange but while walking in Skyrim I have the same feeling as when I'm walking in real life. Sometimes I drift off and loose track of time only to be brought back to "reality" by a frostbite spider spitting venon at me from a distance.

What a great list of little details. NPC conversations, insects, cave streams, NPC comments on your status, the sounds of nature, the journals describing every day life, and more.

I too loved the Whiterun cave with the skeleton hand reaching for the mead. What other little jokes are there like this?

Some of the traps are really clever, like a mammoth skull which swings at you, placed in a cave of mammoth hunters.

Speaking of journals, there are a TON of books in this game. Each contains actual, well written text. I've collected a bunch and placed them on my home's bookshelf. Some day, I'll sit by my fire, eating venison, drinking mead, cozying up the ubiquitous "Beggar Prince".

To heap more praise on the sound team, I recently noticed that the sound of footsteps is subtly different on stone floor and stone stairs. This helps when sneaking, telling me where a guard is in his rounds.

I would like walking around in nature more if I could look around while walking. I play in 3rd person view, so I can place the camera other places than behind me and adjust the keys I use to walk "forward". But I'm still at risk of walking off a cliff or into a sign post. I really wish there was "slow travel", where the game would automatically have your character walk on the road, but let you move the mouse to look around. THAT would be relaxing.

All good stuff. What else?

You can shout them out of the air too.

For some reason, you can't burn them with fire tho ...

I like how there's a mystery guest in my house who moves all my stuff while I'm out. I swear I've seen a herobrine-looking thing out of the corner of my eye as I entered honeyside one time.

I like how the guards often respond to different things continuing on what your character does like if you finish certain quest lines like DB and TG. The best quote I ever heard from a guard was "Psst, I know who you are, Hail Sithis." or something like that lol.

After playing the game today, now with the thread in mind I notice a lot more of the little things I love. I like running on the road, seeing smoke rising from beyond a small hill, or clearing in the woods. It makes me actually really want to check it out, carefully. I love also all the insects, on the stumps and flying around, smashing them with a mace then looting the parts off the ground is very satisfying as well. There are so many things Skyrim did to add 'realism'. I love the way the game makes me feel like I'm actually playing in the time period it's set in.

Anyone else reminded strongly of Renaissance Fairs while playing Skyrim?

You can attack bugs lol? I thought you could only catch them.

Theres so many things ive seen that really add to the beauty of this game
the way the leaves fall from the fern trees (mostly noticeable in Riverwood by the bridge near the water)
the look of the ground textures and sky look amazing i dont know weather to stare at the beauty of the clouds or the pebbles on the ground lol
i love the way the transition of the ground is done also, if you take a second to look where you step you see pot holes in the road and they do effect the height of the terrain your standing on (which again is a lovely touch and looks good)
the eagles that fly above solitude, the first time i saw the shadow on the ground i thought nooooo dragon ruuunnnn! then i looked up

I just like nature on the whole in Skyrim. The fauna, the insects flying around, the salmon leaping up waterfalls and rapids. I feel like fast traveling is such a waste whenever I stop and look at that sort of stuff. Also, the little things that are in almost every dungeon that makes it unique beyond the structure and the enemies within. Journals of bandits or hunters or adventurers, banter between the enemies, certain creatures having dragged off one or a lot of inhabitants, that sort of thing.

If you use a shout/spell on bugs, they stop flying around and simply drop to the ground in the form of whatever ingredient you get for catching them. Butterflies become Blue/Monarch/Luna Moth Wings, Tochbugs become Torchbug Thoraxes, etc.

All the non hostile fauna, I just love the way they're trying to simulate a living world.

A couple more I've noticed. You can't just walk through rapid water - it pushes you and you could go over a waterfall if you're not careful. Also I shot my first elk. It ran away and died a few yards away instead of just immediately dropping dead. Very nice and realistic touch. Makes you find your kill

I noticed for the first time just the other night how a wolf's expression changes when it's attacking. One was charging right at me and got very close before I managed to Calm him - and I saw his face close up: his eyes were wide, with the whites really showing, and a manic feral snarl, all suddenly replaced by the green glow and good-doggie expression when the Calm kicked in.

eyes adjusting to light and bees

The only Ren Faire moment I had was the female bard in Ivarsted addressing me as "My Lady". Moments later when she thought I was looting the chest in her room that I was using to store items, her pleasentries were replaced by a wildly brandished knife, which brought Lidya and the inn keeper into the fight. Couldn't stop them, had to reload.
I never noticed the roads being actually uneven, but I'll check. Yes, the eagles over Solitude are nice. I keep wanting to poach them with my honed long-distance archery skill.
I had the opposite situation. While taking my usual "shortcut" through woods and rocks, I heard an animal snorting sound I never heard before. Suddenly, three red dots in my compass! I was being attacked by elk! What, did they decide that since there were three of them together, that they'd gang up on me? They provoked the fight! Oh well, more Venison Stew for me.
I just noticed this yesterday. Staring at a torch up close, the "iris" closes to dim the view. Looking away at a dark floor, the room looks dark for a second before the "iris" opens to compensate for the lack of light. That must have been tricky to implement.

Anyone notice that normally non hostile animals appear as red dots on the compass when Dragons attack?

Wow there are so many of them.
I like & agree with all the comments so far too.

I would have to say watching the chickens walk and peck the ground for food.

Last night i came into a town (don't remember that name) and everyone was running out into the street and pointing into the sky, so I looked where they were pointing and there was a Dragon flying. The pointing followed the course of the Dragon too. Very Cool

all insects and of course the wildlife and fauna

Interesting question, because there are so many little details, sometimes things you don't really notice, which give the game its realism and massive appeal.

Earlier I did have to smile at the game. I'd just left Breezehome with Lydia to go off and sort out some Bandits. I wanted to give Lydia some Orcish Gauntlets, enchanted for two-handed attacks, but due to that bug where she seems to get weaker and weaker, I wasn't able to ask her to carry my burden. Instead I dropped them on the floor to ask her to pick them up. However, as soon as I'd dropped them someone piped up, "Do you want that armour you just dropped, or would you mind if I took it?" I had to tell him to "Don't touch it!". Was a new one on me.

Also, in a shop earlier I'd noticed some pots and pans strewn about the place, so I started tidying up. (I'm a bit OCD like that sometimes!) The shopkeeper said things like, "What are you doing that for?", and "Careful with that!" when I picked up a pot to place it back on a shelf.

That's easy for me. My favourite little detail is, that I can kill the hawks with fireballs. That makes for me a lot of fun.

The quality light refraction of the gems

Since 1.4 I have noticed that more and more animals are not attacking on site, but holding back. Maybe it is because I am at a higher level now.

However, I was walking along the trail and heard some barking. I started looking for the Stray Dog. I saw it up the hill from me, but it was getting dark and did not look like any dog I have seen in the game. Turns out it was a Wolf barking at me. I stood there long enough that it charged me.

I had never seen a Wolf bark before. Only growl, howl and squeal.

I love the insects. I was out at night and saw fireflies! I spent a good 20 minutes chasing them down and collecting them!

After doing Skyrim's MQ, I'm taking some time to play Oblivion. I keep wanting to reach out and snatch the butterflies in Cyrodiil and you can't, so it might be that wonderful detail they added to Skyrim.

Seeing a sunsets fiery orange glow shining through the open spaces of trees in a snow filled forest.
The wind chime like sound of bones hanging in dungeons or when fataly shattering a skeleton into pieces.
How so many areas tell a story if one takes the time to pause and observe the environment.
Tombstones and graves i find in the wilderness on my travels.
The small insect wildlife and things like bees nests.
The mammoth graveyards and bones across the landscapes of Skyrim.
The variety of traveling npcs on roads from poachers to bards and hunters.
Coming across farmers who will buy certain goods that other places wont take like potatoes.
Shrines which honor the dead.
How everything seems to have its own immersive audio effect making the world so realistic i sometimes wonder if i could play blind and still survive.
Finding things like pearls and clam meat as well as going clam diving.
Seeing smoke and or fire in the distance which is a dead give away for anyone not trying to draw attention to themselves.
Tapping the r key to put away an arrow i already have drawn to be fired. No more wasted ammo or looking for arrows i didnt need to shoot.
The music of Tes 2 Daggerfall in taverns.
The sound of eating and drinking by npcs.

"Hey guard, my fine's been paid! Let me out!"

"What's that? My ears don't work so good."

Hahaha.