There wasn't a bunch of gratuitous violence. What made this movie great was that it didn't capitalize on anything, because it was realistic. This isn't so much a film as an experience. Who hasn't been curious about what a monster attack would really be like? Cloverfield delivers that experience without one-liners or slo-mo action scenes. It doesn't even have any music-- none of the comforts that hollywood normally provides us with. Why? Because this isn't a movie. It's a video tape from an actual monster attack. It's about as real as a monster film can get, and the ending only makes sense. If a huge monster attacks your city, you'll probably die.
If you want a hollywood monster movie, go watch the 1998 Godzzilla. If you want a new experience that you'll never be able to have otherwise, see Cloverfield.
On a side note, I think the rifftrax for Cloverfield will be a disaster. As a riffer, I'm just not seeing it working; not because I think it's perfect, but because I just don't think it's a film that lends itself to riffing. I could be wrong, but I'll be very impressed if te rifftrax is any good at all.