Or the part where he sacrifices his True Companions in order to pull a Click Hello on Blondie - with his spurs. Simultaneously an instance of dog-kicking and an awesome moment for the character.
The amazingly rousing music, courtesy of legend Ennio Morricone.
"Were you gonna die alone?"
Angel Eyes' introduction. It's so damn evil it crosses the line into awesome.
Tuco trying to find the grave that the gold is buried in. He runs through the graveyard, searching every headstone, but as the shot continues, with Tuco running through an endless forest of headstones, one begins to get a sense of perspective, of just how insignificant these three men and their petty struggle is compared to what is happening in the world everywhere they turn. Hundreds of thousands of men are dying in this war, and three vagabonds fight over a pile of money.