The most awesome part ... hard to say really. There are a lot of awesome parts in this game. It sure is like no other game I know. It is the freedom of exploration, all the many details that went into it, the every increasing realism from the weather to the people, the story telling, ... but the most awesome part is its amount of caves and ruins!

I nearly got epilepsy from looking at that lol

Most awesome part would be the random encounters, especially with the Thalmor scum that I kill.

1. The brutality of combat. The thuds, crunches, slashing, screams, and splattering of blood are wonderful.

2. The beautiful views available throughout Skyrim and it's atmospheric dungeons.

3. The freedom to explore where I want and come across points 1 and 2 above.

Sorry I couldn't keep to just one point

There are lots of things but this right here is awesome! I am addicted to archery. I now have this bow that fills up a soul gem when i get the kill. i love to shoot enemies across the map so to speak and then their soul comes swirling over to be absorbed by whatever soul gem I have available.

Random encounters.

Sawing logs at the lumber mill............. And sometimes ridding the log into the blade

Argonians.

And adventuring and exploring (without the compass markers so it's exciting). I also like it when it's stormy and raining in the game.
Edit: I also like exploring dark caves and dungeons. With mods they became dark enough.

For me, the lore. It keeps me playing

ah just a note the thing i linked to isnt just an animated image

its slightly interactive move your mouse about the screen

The fact that I have the PS3 version, which means I can trade it in. Hahaha. But seriously... I haven't had a "That was awesome" moment yet.

Pausing for a moment outside after a dungeon quest and watching http://i1254.photobucket.com/albums/hh611/Trace9569/HPIM1226.jpg The errr "sun" come up. Time and time again, the "world" amazes me. ( I've seen some of the pc mod's and they make the world look even better )

The sky and Blackreach are by far most awesome. Lately begun thinking less of the game, Oblivion just seems all together much better made...

Only thing keeping me playing is lore on snow elves and wanting to know as much as possible.

The butterflies. Really. That such a tiny part of this game is so awesome, blows my mind.