Best airfare tracking site for flights to Europe 2017?

Momondo.com is my favorite with Google flights at a close second. I often find Momondo has the better deals.

I use kayak or www.itasoftware.com, but keep in mind that many schedules are not posted this far in advance and tracking flights works best within a certain time window because airlines on competitive routes are trying to match fares and, at that point, they have some way to gauge demand. I track about 6-8 months before the trip but not earlier because the information won't be credible too far out. Also, not all airlines participate in third-party comparison sites, so you'll have track them separately using their own website info.

I don't do deal notifications, I use a spreadsheet to compare kayak to the actual airline. Kayak will give you a price using mutiple airlines, and I only like using one for my flights (and partners). I also suggest signing up at Travelzoo.com, they will send you a weekly "Top 20" deals and if you are not flying open jaw you can get some fabulous deals. I was able to book a round trip flight from LAX-Heathrow on Air New Zealand for $700.00 each back in 2008 through Travelzoo, it was a flash 48 hour sale and since I had been tracking prices for a few months I knew that was a great deal. If you don't track the high and low prices, then you wont know a deal when you see it.