I loved Skyrim the very second i entered the game - How amazingly detailed it is. Started the main quest chain and killed Alduin at lvl 12 with a pants bow.
Which is exactly why I went out of my way to avoid the main quest line and do everything else first, to get he most out of it. But I succumbed in the end and did Alduin at 50, which was a good point to take a bit of a breather.. and then start messing around with a few quest lines I missed.