To The Moon (basically Hachi in video game form in terms of pure emotional carnage)
 

To The Moon is an Indie Game about a pair of scientists who have the technology to change the memories of a dying person so that they can experience their life over again with their biggest wishes realised. The story is amazing and it'll leave you emotionally scarred. The gameplay is a bit crap but it's basically more of an interactive story than a game really. Go buy it, you can get it on Steam for a pittance. It's an experience.