I watched the movie "I am Legend" today, and I must say that I far prefer the novel.
Good things about the movie:
The depiction of an empty New York was excellent, and that was worth the price of admission itself. Seeing the bridges collapsed, the animals taking over, the abandoned cars and so forth was the best part of the movie, I thought. I enjoyed how the movie explored the loneliness and isolation that Robert Neville experienced, and how it discussed some scientific explanations for vampirism. The idea of using an antivirus to cure vampires was quite good. The movie also managed to show some aspects of Robert Neville's life far better than the book, such as the lockup system, and so forth.
What I did not like:
Although the movie had some scary moments in it, I thought these were usually the cheap "out of nowhere surprise" type of scare, such as the lion attacking the deer, and so forth. It also removed most of my favourite aspects of Richard Matheson's novel, such as seeing Robert Neville change from a character that merely huddles out of sight, to a merciless vampire killer. such as scientific explanations for vampires. The reason behind the woman finding out how to meet Robert seems far too cheap an explanation.
However, I far prefer the novelisation.