Best site for airfares to Europe?

Google Flights is my go-to; it has:
- price alerts
- price calendar
- map view: you can pick "Europe" as a destination and see which city is cheapest to fly into
- all the filters you may need

and it redirects you to the airlines' websites for booking, which is crucial. The few $$$ sometimes saved booking through a third party bring no end of problems if something goes wrong with the flight and you need to reschedule or get refunded.

The days of third party consolidators dealing in leftover discount tickets is long gone. I'll use Orbitz or Travelocity to see which airlines go to my destination, and then go to the actual airline website for purchase. As many people have found out in the last couple of years, booking through third party sites can create complications with changes and refunds. Some third party sites were showing fares without including all the taxes and fees.

Google Flights is my go-to; it has:
- price alerts
- price calendar
- map view: you can pick "Europe" as a destination and see which city is cheapest to fly into
- all the filters you may need

and it redirects you to the airlines' websites for booking, which is
crucial. The few $$$ sometimes saved booking through a third party
bring no end of problems if something goes wrong with the flight and
you need to reschedule or get refunded.

Ditto

One source of information I use is Wikipedia for the airport--by name. Someone maintains present and future flight information into and out of every airport in the world. And the information is updated immediately upon changes.
By knowing what airline flies where, I can easily figure out how to get more non-stops at the times I want.

For example many budget flights get you into Europe at 6:00 a.m.--7 to 8 hours before you can get into your hotel. I avoid that.

I mostly use the Matrix ITA Software format which is owned and associated with Google Flights. I try to buy tickets directly from airlines after having a very negative experience with a big flight online flight seller last year.

Totally agree that Google Flights is the very best. I usually find good fares from GF and then book from online travel agencies or airlines. One benefit of one travel agencies is more inter-airline choices, esp. for open-jaw flights. However, you should feel comfortable that some of these agencies, such as Travelocity and Expedia, provide subpar customer service.

David, try GoogleFlights. A great tool is from a city to "Europe" nonstop. It's how I piece together trips. I want to go to Budapest for 2 weeks, and Odesa for a week. But I have a week between the two. What to do? GoogleFlights will tell me all the nonstop flights out of Budapest and all the nonstop flights out of Odesa and then my options are the locations in common between the two. Walaaaa, Sofia! (or not)

I use Kayak.com and/or matrix air to end the best deal, then go to the airline to buy the ticket.

Since we prefer flying on Delta if the Delta's price is close to the lowest, we go with them. For domestic flights Delta, American and United are usually very close in price.

For overseas travel, again prefer Delta, Air France or KLM which we book 95% of the time.