Ninja Gaiden/Awesome

Ninja Gaiden NES

 * The opening cutscene, featuring the dramatic Single-Stroke Battle between Ryu's father and an unknown enemy, followed by Ryu reading his father's mysterious will. This, more than anything else, sets the tone for the entire series.
 * Ryu cradling the dying Dr. Smith in his arms. Just as he passes on, he looks up and sees a trio of men in black holding guns at him saying, "Come with us".

Ninja Gaiden II: The Dark Sword of Chaos

 * Again, the opening cutscene takes center stage, firmly establishing Ashtar's Magnificent Bastard credentials. Later events in the game would do nothing to dissuade anybody watching this scene from believing that Ashtar was one of the great villains of the NES era.
 * The entire cutscene at the top of the Tower of Lahja. Ryu arrives just in time to see Irene swept away by Ashtar, who then blasts Ryu with his Sword of Chaos.
 * After Ashtar is defeated, the cutscene switches to the Sword of Chaos vanishing into thin air. A very cool piece of foreshadowing in an era not known for such subtlety of plot.

Ninja Gaiden III: The Ancient Ship of Doom

 * Irene's return.
 * Foster's death at the hands of Clancy.
 * Ryu's reaction to the third boss in the final boss battle.

Ninja Gaiden Xbox

 * In the second game, when New York  City is under attack, Ryu is seen atop a skyscraper. He pulls of his trusty bow, shoots a fiend in the throat, jumps onto it, and rides it down to street level.