Europe and the US have had a symbiotic relationship since the creation of the colonies. This relationship may not have always been civil, but it has always existed. Because the media in the US contains valuable data as it pertains to national and international issues, it is often viewed by Europeans in order to predict how they should act. This does not necassarily mean they comply with US trends, but Europeans absolutely use American media to make decisions. Everything from music, to fashion, to political and military tactics. All of these are molded in reaction to American media, and vice-versa. The US is not above European influence for the same reasons.
American media is greatly responsible for effects on European culture. The media, coupled with the Internet, is changing European culture, making it more like our own. As we develop close relationships with the European countries, we continue to be a role model, with the media making subtle changes to their culture, making it more like our own.
Media is infectious. With the internet, there isn't a place on this planet that it cannot get to. Shows popular in the USA will be popular in other countries. The United State's culture will spread. This will affect every other culture, Europe especially because of the many similarities in culture. The US news media also has an effect in Europe by propagating the US's political beliefs.
I don't think European culture is being directly influenced by American media. Europe has become strong over the years with the establishment of the European Union and their culture may be considered the leading culture now. I don't think enough of them pay attention to the American media to be influenced that much.
The Europeans are way further ahead of us in everything they do. Their eating habits are better and for some reason our country doesn't care about the people that live in this country at all. The Europeans have banned GMO's, Americans haven't complained loudly enough to say no to these things. They are way more advanced.