First of all, it's a zombie movie. It feels very painful to write Legend off simply for that fact, but at the end of the day, despite having a powerfully moving story, the conflict revolved around creatures who shuffled around New York City looking for brains. Granted, they were a fair bit more intelligent than your usual zombies, but except for the head zombie, they were about as three-dimensional as a piece of paper. It also didn't help that about three-fourths of the way through, the movie abandoned drama and emotion for gunfire and explosions. Yes, the ending shifted back, but too much of the emotional weight had been lost already for it to be truly moving. I think Lanzador put it best--as we were leaving the theatre, he said (SPOILER ALERT) he was more moved when Sam (Will Smith's character's dog) died than when Robert (Will Smith) did (END SPOILER ALERT), and I had to agree.
Also, Will Smith did an amazing job as Robert Neville, but he seemed a little "too cool for school". It's hard to say that a better actor could have been found to play the role--I bounced this point off Lanzador and neither of us could think of someone else who would have been nearly as good--but I thought Will Smith seemed a bit too...in control, I guess, considering he had survived the zombocalypse. I wanted to see someone a little more world-weary, someone I could tell was bearing an enormous weight on his shoulders, someone like Tommy Lee Jones or Clint Eastwood, but with the tough-guy persona turned way down. I liked that Neville talked to mannequins, going so far as to give them names and worry about their safety--it successfully showed the mental toll that being the last surviving human would take on a person, and I wanted to see more of the same, to get more of a sense that Neville was barely clinging to his sanity.
The ending was good and it made sense for the story, but I wasn't quite sold on it. Maybe it was the whole explosion thing, but it just seemed a little too...convenient: (SPOILER ALERT) Neville finding the cure, the butterfly, the restoration of faith, and the self-sacrifice (END SPOILER ALERT), it just seemed like too tidy a package. I know, all movies need satisfactory closure, but that was the first time it felt like I was watching a movie, as opposed to being immersed and surrounded by it. Of course, the obviously CGI zombies didn't help either.
Despite all of this, Legend was the best movie I've seen in a very long time, and I highly recommend it to everyone, whether you're looking for heart-wrenching human emotion or some good old-fashioned zombie killing.