Korea has put out some fucking slick films in the past decade. Oldboy being one of the best.
The Host is very unique in that it skips from genre to genre, and still feels like a seamlessly organic experience. The comic relief feels natural, the chills and thrills authentic, the messages subtle and effective, and the characters deep. And to top it all off, the monster is eerily ruthless and believable.
Best moment that I recall from the film is when the father and son are walking in the rain [ by the river, father about to face the creature] and the father gives the son such a powerful look. Its a staggering moment and sets a tone for the rest of the movie.