New ways to fly to Europe
It seems 2017 will be the year of long haul discount airlines. More and more smaller/larger companies offer cheap tickes from the USA to Europe or even from Asia.
These flights are different a bit than the 'old' way. Like some companies using narrow bodies airplanes or/and you have to pay for every step. Luggage/food/seat reservation, etc. And you have to think far in advance as tickets are the earlier you buy the cheaper you get.
Which companies are we talking about?
Norwegian is in operation for many years as discount operator for inside Europe lights. The idea came to fly cross the Pacific to USA as they got their new Boeing 787s. Yes, you can fly with brand new Boeing Dreamliners.
Usually you have to change plane if you'd like to reach some destinations, but they serving Baltimore/Washington (BWI), Boston (BOS), Florida Fort Lauderdale (FLL), Florida Orlando (MCO), Las Vegas (LAS), Los Angeles (LAX), New York (JFK), New York Newark (EWR), San Francisco Oakland (OAK) and you can fly with them to London or Paris also, not only to Norway :-). Plan more destinations as they will get the new Boeing 737 MAX8s.
Wow Air is low cost carrier based in Iceland. Started operation in 2012. And serving many US destinations like Boston, San Francisco, Los Angeles, Washington D.C., New York Newark, Miami, Pittsburgh. Wow Air is using Airbus A321-200 (narrow body) and Airbus A330-300 (wide body) planes.
Works similar to Norwegian as you take a route from USA to Iceland, than change to next flight inside Europe. Worth a seach for fares.
Scoot and AirAsia X
Asian low cost airlines are a little behind, as they concentrating the big asian marketplace first. Scoot is flying with Boeing 787 from Singapore to Athens. AirAsia X, which tried to connect the two continent previously, is about to restart operation, but waiting the new planes to arrive.