I just made a new list Great Gaming Moments I'd be interested in hearing about anyody elses memorable moments, those key moment in gaming that you remember fondly.  I suppose to compare it to cinematic examples, that bit in the Lord of the Rings I'd be suggesting parts like, Gandalf just before escaping from Saruman on an Eagle says, "There is only one Lord of the Rings; and he does not share power!" Or the pit in The Two Towers where Gandalf fights the Balrog... The battle scenes... If we thought 'Star Wars' I'd be thinking of the duel between Obi-wan and Darth Vader in Episode IV... That sort of thing.

Dude, MGSIV. Particularly the microwave tunnel and the Metal Gear battle.
 
Heavy Rain finger chop.
 
The death of Roman or uh...Packie's sister in GTAIV
 
The first time you fly in Super Mario 64.

The Darkness

Persona 3's ending
 
Meeting Revolver Ocelot in MGS3

heavy rain- just the entire game. it felt like a movie or something. when you took a break you wanted to know what happened next. there was a lot of emotion in this game that if you connected with it you felt kind of sad. 
 
mario 64- pretty much a new generation of video games. you just were amazed at how the graphics looked when mario went 3D. the new adventure to find all of the stars.