They say that a movie makes most of its money in the first couple of weeks. So it is always interesting when a film has a come back as happened with Narnia, which took back the number 1 spot from King Kong over the Christmas holiday. The BlogPulse trend graph reflects this:
One might conclude that Kong's strength was its special effects, certainly not its musical score. However, Kong had more humour in it than Narnia. Of course, these analyses are very ad hoc and would require certain types of normalization to make them truely comparative, but you get the picture.