Vampire lord (lady to be exact). I re-rolled a dark elf archer/assassin and at level 26, VL powers rips everything a new one. I don't use it much in dungeons as I'm still leveling but if I am exploring the map at night, I use VL since their sprint (flying of sorts) is pretty fast and can easily dispatch anything that gets in my way. I already maxed out my perk tree by randomly killing things while exploring the countryside.
Not as a high level as your, but that is what I am doing. Exploring the countryside and killing and leveling up that way.
Also I find a usefullness for restore staminia potions. Never used them before, but man, am I using them up alot now.

Almosts feels like Morrowindish.