Slimebeast on 04 October 2010
The ending of Oblivion's main quest obviously. (I won't spoil it here)
Morrowind's main theme:
http://www.youtube.com/watch?v=ZWuNf4gxwuM
Some parts of Dragon Age on your relationship with Morrigan.
Most of Sierra's Conquests of Camelot. Poor King Arthur. The intro has one of the saddest melodies in history:
http://www.youtube.com/watch?v=BZGC0UcG2bk
