I Am Legend
I enthusiastically saw "I AM LEGEND" back in October when it opened on film. Will Smith is an underrated actor who has a great presence and an impressive range, and he totally shines in this movie, which is a fairly faithful retelling of the book by the same name.
A central theme of the book was bogged down and drowned, though, in the film adaptation, and the alternate ending that's available on the DVD would have done a better job of bringing that important theme -- about the nascence of human nature after extreme cataclysm and the monstrousness of what was once normal -- back into the film.
If you want to see this alternate ending, it's available here: http://www.firstshowing.net/2008/03/05/must-watch-i-am-legends-original-ending-this-is-amazing/