EQ had all sorts of crazy triggers for quests. And made WoW's problem of quest interference seem palty by comparison. In order to complete the Epic Weapon quest for Rogues, basically the quest that defined your class and gave you a weapon you'd likely never stop using, it was like a 6 stage quest which one part of required around 30 people. About 20 to do the actual fight that eventually happened, and another 10 to try to run interference around the quest spot to try to prevent other players from wandering in and literally, unknowingly, sabotage months of work involving utterly insanely rare spawns. I'm talking, a server sign up sheet and multi-hour vigils to watch for spawn and/or spawn stealing level of rare spawns.
I can't even conceive of playing such a game today, and yet in its day, I was completely enthralled. I think EQ is when I truly woke up to video game's ability to manipulate your mind, emotions and motivations. Never have I felt such highs, or such lows, playing a video game. And honestly if another game came along in the future that made me feel that way, I'd seriously consider not playing it as potentially destructive to my life. I may have skipped this or that or called in sick to play WoW sometimes, but never did WoW leave me a quivering mass of "what does my life mean if the last 2 years of what I've spent it doing can just vanish?"