Skyrim has some pathetic excuses for bosses, but it also have some quite difficult to mind numbingly annoying bosses. I want to know what are some of the hardest bosses that you have ever face. Would like to know which one is mentioned the most. Try to include named ones as much as possible, describe how you defeated it if you want, and if it contains spoilers, do everyone a favor and use spoiler tags.
I have faced plenty of hard bosses in the past, but I must name one that I dealt with just recently. Dragonborn DLC spoilers:
I'm sure many of you have experienced something similar with other Dragon Priest.