The wizards duel. It may have had zero CGI, and only lasted for a few moments but. Damn in those few moments Akiro was totally BADASS!
If you watch closely, you can see how much effort the wizards exert in the duel; smoke comes out of The Leader's nose at one point, and at the end, it looks like steam is coming off of the victorious - and visibly exhausted - Akiro. Hardly any visual effects in that scene, but it's the acting of Ferdy Mayne and Mako that make it work.
The scene is a Moment of Awesome for the characters, but also for the actors, who clearly depict exactly what the wizards were doing - without need of any running commentary for the fight.note Akiro first uses his magic to counter the Leader's spell to open the door, and so tricks the Leader into using all his power to force open it, then switches from struggling for the door to attacking him directly, smoking his brains off.
Conan's cunning and crafty defeat of the Guardian, the wizard Thoth-Amon, along with Awesome Music was pretty damn epic.
Conan's final fight with Bombaata was pretty impressive.
Dagoth, the (semi) resurrected god of evil v.s. Conan:
Winner = Conan
Want a real subtle Dagoth CMOA? They needed an actor that was physically imposing enough to tower over Arnie, strong enough move with giant layers of rubber costume on, AND still able to put up a convincingly choreographed fight? Who could do such a task? André the Freaking Giant. Who went totally uncredited for the role for years.