The original Highlander movie more or less codified the Crowning Moment of Awesome with the Quickening (No, not the awful movie). What could we do to make a swordfight more awesome? Oh, how about when one of the guys takes the other guy's head, EVERYTHING EXPLODES!
The church scene in the original film. Never before has two men sitting down and talking been more badass.
Connor letting the Kurgan know that any fear he may have felt is long gone: "You can't stay in here forever."
Connor defeating the Kurgan.
Brenda attacking the Kurgan with a pipe also qualifies, given she knew she was attacking a six foot tall, immortal, madman wielding a broadsword.
The duel between Ramirez and the Kurgan. When Sean Connery is demolishing brick walls due to the impact of his sword, you know that Awesome is occurring.
The gun nut who stumbles upon the end of a duel and opens fire on the Kurgan. No, it didn't work, but he still did better than just about anyone else who went up against the Kurgan.
Also awesome: after getting impaled on the Kurgan's sword and left for dead, the gun nut lives.
Subtle, but there's Connor coolly weaseling out of the policeman trying to get him to implicate himself. Twice.