Mine has been in "The Summoning Pits" on Moon, called "The Untamed". Ridiculous health, constant high damage beams and never resting minion waves. It's not impossible, but if you get there low level and no back-up, better say your prayers haha
So, what's your most hated boss nemesis?
-
VoG - Spires. When the zone lags and every Vex that the entire fireteam just saw die for the last 4 seconds appears directly in front of the spires.