I prefer the third person, because it allows the writer to take a more omniscent approach. You can have multiple subplots going on at the same time, in completely different places, with different people, or you can reveal things the main character doesn't know (i.e. dramatic irony).

You are limited to what the character sees and hears in first person (this can be done to your advantage such as more surprising surprises and getting more in-depth with the main character, but that doesn't mean you can't achieve the same results with third person). The few books that I've read that uses first person are actually very good but since I still like third person more, I suppose I'm just writing this from a personal point of view.