Ryld's utter demolishment of the drow rogues after he enters his trance, particularly when he takes on a bard, a drider, and one of his former students and wins.
His fight with Jeggred counts as well, even though he ends up dying. He holds his own and heavily injures a freaking Draegloth, including chopping off one of Jeggred's hands.
Quenthel's various battles against the demons Gromph sends after her are awesome, as she manages to do with absolutely no spells aside from the stuff she has stored in some scrolls and manages to thwart and eleminate assassination attempts from other priestesses as well.
Also her attempted double cross of Pharaun when meeting the aboleths, while it didn't work, deserves credit for how clever it was since it was something she and her snakes came up with at the spur of the moment.
Pharaun's destruction of Belshazu in revenge for destroying his rapier, with an extremely powerful shout spell that literally tears him apart.
His killing of the leader of the Yugoloth army is awesome as well due to being utterly paralyzed and heavily wounded at the time. He encases him in a giant force hand then incinerates his head with a fireball