I have just finished KiraKira and I loved it, but after watching the true end I got especially emotional during the scene were..
The protagonist watches Kirari's father bleed to death without doing anything but watching, since he thinks it is the best choice for Kirari
I really liked this scene and the internal conflict in the protagonist. The way that the story explored the darker parts of the human psyche from a first-person perspective really got me thinking. I have played a lot of V-novels and eroge, and even if the protagonist sometimes does deeds that can mildly be expressed as mean or coldblooded, those characters often come across as unrealistic and psycotic/evil. Bible black as an example, when the protagonist finally snaps and becomes evil, you can't relate to the character at all anymore.
Long story short: I am looking for more games that portrait normal people faced with hard choices. I would love a story about a normal person who falls deeper and deeper into a life of crime/immorality and see his gradual change without loosing his core character. I don't care if the story end happily or sadly, the character development and dilemmas is what I am after.