Steven Messner: Good in MMOs
At the risk of accidentally drawing Tim's ire, I will bring the MMO perspective here and say that boss fights are a universal good. I mean, MMO dungeons and raids are basically boss fight gauntlets, and it's what makes those activities so damn fun. There's obviously a lot of salt and tears that comes with running a raid boss for the first time, but MMO boss fights bring something to the table that you don't see in any other genre: coordination.
I love the idea that every member of your party has a crucial role to play in a fight, and the way a well-designed boss fight layers mechanics upon mechanics. You're not just tanking the boss, you're tanking him while managing a stacking debuff that requires a timely tank swap, soaking fatal hits with active mitigation abilities, positioning the boss so that he doesn't accidentally cleave the party,
and taunting any monsters that spawn so they don't curb stomp the healer—it's a lot to remember and it gives boss fights this frantic, terrifying pacing. But when you master that same encounter, it suddenly becomes a beautiful group choreography as each player moves perfectly to the rhythm of the boss' abilities.
I probably shouldn't have written this days after downing Aggramar, the final boss of WoW's current raid. I'm riding a potent high right now.