Yes. I've been touched in terrible, terrible ways...
Oh. You meant emotionally?
Well, the first thing that comes to mind is on the New Alexandria mission of Halo Reach, since I was only playing it yesterday.
To anyone who hasn't played the game, New Alexandria is the capital city of the planet Reach. The previous mission you helped evacuate thousands of civilians from the besieged city, and in this mission you are flying through the city at night, with fires in the distance.
Anyway, about two minutes into the mission, as you fly towards your objective, listening to distant explosions, the screen starts to shake as a Covenant cruiser veers overhead. It stops several miles away, and a few seconds later a massive beam of energy utterly devastates the ground underneath.
The sound, the visuals... It was fantastic. That single bit of the level made me understand why "glassing" is so terrifying for humanity. Nothing could stand up to that onslaught.