Best Scene in a game.

[Reasonable]

Favorite moments/scenes, etc.

The ending of ICO, after the credits.

Deus Ex when you escape internment, to enter a very familiar location - my favorite twist ever in a game.

System Shock 2 when you finally reach Dr Polito (spelling?) and meet an old friend.

Ending of Shadow of the Colossus

First time you really see Pyramid Head in 'action' in Silent Hill 2

Looking into the mirror in Silent Hill 3, and coming to the conclusion your reflection may not be totally with you anymore.

And my all time favorite - the ending cinematic of Grim Fandango. Manny and Meche go to a better place. Even as an Atheist I was willing to buy they were actually going somewhere.