Zoltan Kulle Fight Glitch
This glitch is particularly reminiscent of the battle with Mephisto in Diablo II. On harder difficulties—and with the use of a Sorceress, you could trick him into trying to attack you from the corner of a platform. In doing so, you'd be tricking the pathfinding routines and Mephisto would find himself unable to move out of the corner. He'd be completely vulnerable to your ranged attacks. The same thing can be done with Kulle on the invisible bridge.