Add Stockholm to your list: the Nordic city is receiving some great new flight options this spring. Shutterstock When airlines announce new service between two cities, it doesn't just create more flight options. It also drives down airfares.

This spring, new routes from major carriers like American, JetBlue, United, and Virgin America will mean big savings on service both in the U.S. and abroad.

Here are the 10 routes with the best potential for bargains.