Norwegian Air Shuttle has some amazing fares on their direct flight between New York City and Stockholm, Sweden. The flight is operated by a 787 Dreamliner with nine across seating in coach.
Secret Flying is reporting fares as low as $297 roundtrip in February, 2016, although I was able to find fares in the low $300 range for much of this year as well. Note that the website will price out the tickets in USD, but you may be able to save additional money by paying in Norwegian Krone and using a credit card without a foreign transaction fee.
Norwegian is a low cost carrier, so keep in mind that baggage fees, seat assignments and food are not included in the fare. They also do not have partners, so the mileage earning potential is limited. I always recommend taking these factors into consideration when determining if the deal is right for you.