Gandalf’s battle with the Balrog in the Mines of Moria is probably one of the most breath-taking, edge of your seat fights in the entire trilogy, both because of the impressive visual aspects of fire and smoke in Peter Jackson’s film adaptations, and because of the high stakes involved, of Gandalf giving his life to protect his friends, and give them a chance to escape safely out of the mines. His loss hits the fellowship hard, and they break not long after this, without his guidance, which goes to show exactly what a sacrifice he makes.