What is the most annoying boss fight you can think of?

[Madame Adequate]

Vesper and Decus from Star Ocean 2. I'm a pretty god damn good player of that game, I've spent more time than is healthy with it, and I can handle damned near anything else including the final boss just fine. But those guys? Unless I plan perfectly they will wreck all of the trout.

"BURNNNN TO DEATH!"

e; Also Tarnesh. Once you know how the game works he's no big unless you get bad rolls (but that's the way of things). First time you roll on into the Friend Arm Inn, with all of Imoen, Montaron, and Xzar at your side? He's gonna pop Mirror Image, fear your guys, and break you upon his body.