LogFAQs > #980089946

It's not a specific boss, and I know most of you will scoff at the notion of Skyrim being challenging, but the midgame will kick your ass if you aren't prepared. Levels 25-30 are when some of the game's toughest enemy classes start appearing (particularly bandits and draugr), and plenty of new players get to that point very quickly and without having put a lot of thought into their leveling, resulting in their skills being spread too thin and not up to the task of going toe-to-toe with the beefy new enemy classes. This tends to mellow out by the time you get into higher levels and start maxing skills, thus making Skyrim's middle the most challenging.