[gregebowman]

I think that the real reason why humans, earth, and/or the Americans are always first or victorious in the end is that simply, humans are making the movies, and most of the time it's in American movies. I don't think the paying audience would go see a movie in which the aliens come out on top (unless you're talking about Aliens from the Alien movies). We want to see us being the good guys and be able to win in the end.