I really like 28 Days Later. It's got a real message to it, but the second half is light on the scares and heavy on the political and social commentary... so a lot of people dislike it. It's probably come the closest of any modern "zombie" film to mimicking the kind of social commentary mixed with horror that Romero used to excel at back in his early years (not so much anymore). It also has a tendency to be rather overrated in some circles. If you go in with modest expectations and are capable of enjoying a nice blend of genres, you'll have a bloody good time.