There's so many great scenes, like the Intellect Devourers completely ignore the party, and the fact that all of their classes use intelligence as a dump stat. Or how fantastically shot that entire escape from the tower sequence was. Or how clever the intentionally jumping into the gelatonus cube was...
But my absolute favorite scene was when the paladin was walking away and Edgin said oh no there's a rock in his way, will he go around? And he walks straight up and over it. It had us dying, we had to pause it because we laughing so hard.