One of the main airports into Germany is through Dusseldorf Airport. It is a larger international airport, with all of the conveniences of a smaller airport. What I mean by that is that the customs and immigration line is typically very short and when leaving the security line is also typically very short. Of course the majority of people who work here also speak English, making your navigation very easy. The outside of the airport is a little confusing with sneaky stoplights, lots of turn offs into different parking lots and two separate roads that take you to arrivals and departures. Getting here is easy, with returning a rental car being labeled nicely and it's a quick walk to the airport. There is also a hotel right there, making it nice to stay at for early morning flights back to the states. I really prefer flying here vs Frankfurt because of the ease of navigation in and around the airport.