Dansen said:
The Four Kings in Dark Souls.
The second cheapest boss fight in Dark Souls. If you aren't a tank or magic caster you are screwed. The worst part is that even though they have a shared health bar they revive if you don't kill them fast enough making it a dps race.
I saw a comment on youtube that accurately describes the BS of that fight.
"That moment when you find out that there are actually five kings..."
Not true, all you need to be is good at dodging. Hell, there are people who have beaten them at quite a low level. I personally was disappointed with the boss fight, as I heard it was really tough. I think I died more times from forgetting to put on the ring than from the kings themselves. I do however agree that they can be a pain in the ass for the unprepared, and on later a play-throughs. I do find it funny that there is a 5th king though.
As for my contribution? Hrm...I would say Illidari Council in world of Warcraft. Back during burning crusade, it was one of the hardest fights I have ever encountered, if only because everyone needed to be on their toes. You fight several bosses at the same time which share a health bar. You have a rogue that randomly attacks people and puts a massive(at the time) dot on them. You have a priest which heals the group, as well as attacks. You have a mage that can only be tanked by another mage using spell steal, and a paladin which would buff a random member of his party, and make them immune to physical or magical attacks; he also hits like a truck. So all while everyone is either countering attacks or trying not to die, the mage also is throwing around aoe's like its nobodies business. I swear my guild was stuck on that one boss for a long time. They were harder than the main boss of the dungeon himself(Illidan).