As the ghost of a young man lingers in his apartment, he gradually transforms into a vengeful, evil spirit as he gets more and more jealous of his roommates’ lives and becomes convinced that they are starting to forget him

I think this is very interesting and will have a huge change from playful to scary.

The thing it is that it goes kind of deep and is hard to contain in the logline. This guy is someone who died very suddenly, and was at a point in his life where he felt comfortable - he considers himself the "glue" that kept the roommates together. He simply doesn't want to leave what he thought was a comfortable life. It starts to become clear, however, that he sort of craves the positive attention he was getting in life... and now, being unable to do the things he enjoyed, or to have the people he had around him to validate his existance, he becomes desperate for the attention, and this is what rapidly drives him mad.

I like the idea of a ghost hanging around his apartment. Sounds a little like the ghost from Being Human http://www.imdb.com/title/tt1349938/. But I'd like a hint as to why. Feel you need to give us an indication of his desire. What does he want? In Being Human the ghost wants to know first why she is still here. She finds out she was murdered. Then she wants to take revenge on the person who killed her.