This isn't the first attempt to make a movie based on the book I Am Legend. The first movie was a Charlton Heston classic called The Omega Man [Blu-ray]. I cannot recommend that one though. It's incredibly cheesy, and it has no firm connection to the book by Matheson. Sure, you have the weird female dancing, and a "me against the world" plot, but it's so stupid! The new movie isn't as corny as the previous, but it definitely shares a similarity to Heston's.
In the newer movie, you find Robert Neville alone with his dog in a New York city wasteland. A disease has changed everyone but Neville. You get some flashbacks to find out how it happened and how he fits into the picture. It's an entertaining movie. It's a good movie if you have never even heard of the book. And I find that a little sad. When I read the book I really felt that they could do an accurate interpretation of Matheson's novel. It's short and sweet.. has humor and plenty of drama. So why do they move so far away from it? The ending, the reasons, the setting, the creatures, and the main character are no where near what the author directed in the novel. This isn't to say that the movie can't stand on it's own merit, and I wish it would have by being called something like "I breathe hard and hate the light b/c I'm not like you and want to eat deer".
Rating for Movie: 1 thumb, Rent or See on TV, 3 stars, no Razzie but no Oscar
P.S. I cannot wait till The Road comes out on video so we can watch. I'm looking forward to seeing if they do an accurate portrayal of the novel and live up to my expectations.