The best price found from United States to Germany is on May 8th, 2015, travelling with Icelandair. See more options, compare prices and book: search flights.
Frankfurt Airport is the main gateway for transcontinental flights, although Düsseldorf and Munich also receive their share of overseas air traffic. At the time of writing, Berlin had two smaller international airports, Tegel and Schönefeld, but these will be replaced by the brand-new Berlin Brandenburg Airport upon its completion, scheduled for 2013. New to Berlin are direct flights from such US gateways as New York and Los Angeles. There are also sizeable airports in Hamburg, Cologne/Bonn and Stuttgart, and smaller ones in such cities as Bremen, Dresden, Hanover, Leipzig, Münster-Osnabrück and Nuremberg.
Lufthansa, Germany's national flagship carrier and Star Alliance member, operates a vast network of domestic and international flights and has one of the world’s best safety records. Practically every other national carrier from around the world serves Germany, along with budget carriers Air Berlin, EasyJet, Flybe, airBaltic, Ryanair and Germanwings. Note that Ryanair usually flies to remote airports, which are often little more than recycled military airstrips. Frankfurt-Hahn, for instance, is actually near the Moselle River, about 110km northwest of Frankfurt proper.
Timing is key when it comes to snapping up cheap airfares. You can generally save a bundle by booking early, travelling midweek (Tuesday to Thursday) or in low season (October to March/April in the case of Germany), or flying in the late evening or early morning. If you're planning to travel between June and September, it's wise to book well ahead.