Skyrim does not have the best graphics, the best combat or best magic system, but it does have one of the biggest and most immersive worlds I've ever seen.
There's a huge amount of content, dozens of quests, making it more of a quantity than quality game (and that pleases me).
The map is enormous, full of gorgeous landscapes, vast mountains and forests worth exploring.
Many times in my wanderings, I had to stop and look at the mesmerizing starscapes and all the northern lights scattered around the huge full moon. THAT is how I fell in love with Skyrim.

Sound/Music: Truly epic! The music fits into whatever you are doing perfectly.
Leveling up, gaining powers gives you an awesome musical score, the battle songs are intense, especially when you fight dragons. I won't even say how much time I've spent listening to the main menu song.

What upsets me is the central plot. The main storyline focuses on defeating Alduin and takes around 15 hours, which in my opinion is VERY short and it doesn't have that much of an impact.
The final battle was too easy and dull (not to mention the other 3 unnecessary warriors assigned for the battle)...killing Alduin so early in the game gave me an empty feeling.
Besides this, for me there is nothing else to complain about.

Conclusion: The game is gorgeous, filled with hundreds of hours of action, dialogue and quests. Stunning views and landscapes. Incredible and engaging soundtrack. All of these make Skyrim a memorable and immersive experience.