What are the best sites to use to book a flight

I have had good luck with using Google Flights. https://www.google.com/flights/

We like Skyscanner for searching flights but prefer to book directly with the airlines. It's not so much about fees as not wanting to deal with a 3rd-party booker if something goes awry, like a cancelled flight.

Search with whatever tool works best for you. Book on the airline's own website.

I wouldn't take any guidebook's "rules" as gospel (by the way, Rick doesn't seem to have an aversion toward Airbnb or Uber so I'm not sure why Expedia or Priceline is singled out). There are plenty of instances where it's quite useful to have a third party option because the fees pale in comparison to the savings, especially in packaged deals which could be substantial (assuming you can tolerate some risk). It's best to compare for yourself when making the decision and not write anything off. You're looking at getting the best bottom-line price (I assume?), so focusing narrowly on fees is a bit "missing the forest for the trees".

Given you're going to Dublin, I would check out the budget airlines that go there: Aer Lingus and Iceland Air. I've had very good experiences using both direct airlines sites and third party sites. I use ITA Matrix, Kayak, or Google flights to compare options...and some airlines are not on those sites so you have to look at them separately. I prefer to book on airlines' own sites but I definitely use comparison sites to shop around and have no issues buying from a third party assuming they are legitimate and the savings are substantive.

I am a fan of Travelocity myself if you are sticking to one city. I find you can't get a round trip flight and hotel separately for the price you can get a flight/hotel package on Travelocity.

One tip that saved me a bunch of money though is to follow Scott's Cheap Flights on Facebook. I saved +/-$600 on two round trip tickets between Charlotte, NC and London on a tip from him. United tickets dropped suddenly to destinations all over Europe (+/- $500 RT each). Even booking through Travelocity with that info saved me $600 total. I had been looking at trips earlier that morning so that's how I know I saved so much. That info was free but he also has a subscription service (about $5/month). You supposedly find out about better/more specific deals and get the information faster if you subscribe. Following him on Facebook is free but you have to be ready to jump because the deals sell out fast. You don't book through him (use the airline, google flights, or any ticket website for that).

Other good tools are typing Google flights in your browser and searching that way. Also the Hopper app for smartphones is good. You can set up a search for a trip for specific dates and it will give you a prediction on whether you should purchase now or wait and when prices generally drop and go up for a specific trip. It will also alert you if your trip price drops.

As for dealing with 3rd party - I've used Travelocity for several flights and thankfully have never had to deal with flight cancellations, missed flights or hotel issues. The way I see it you are a ticketed passenger so between the 3rd party and the airline they should get it straightened out. I've only called Travelocity twice (not for issues on their end but questions on my end) but have found them to be legit and helpful. I do make a point to show up to the airport early, schedule layovers that allow buffer time, and purchase travel insurance for international trips.

knocks on wood

I booked via Expedia two times to Europe last year but start every search using Google flights. So whatever site that leads you to the best price with 1 connection maximum

Good luck dealing with a missed connection or other significant issue while trying to get to your destination in Europe. I much prefer to book with airlines directly and when issues arise, and yes, they arise, I just skip over to the customer service counter while at the airport and fix the problem...with a human...face to face. To some extent, my approach is influenced by my isolated starting/ending airport.

I like starting with google flights and its more techy sibling ITA Matrix- they send you to the airline's own web site with the full fare construction and ticketing information in place- helpful because it can sometimes create fares and rourings that are hard to find on the airline's own web site.

Dublin is typically one of the more affordable points of entry into Europe. Right now doing a search with ITA Matrix, I'm seeing a number of dates when a 10-12 night September trip has all kinds of options from multiple airlines of one stop (there are apparently no direct flight options) for Seattle to Dublin and back for $600 or less. This is a good price for a west coast transatlantic flight these days, and I'd move on that if you've got firm vacation dates in place.

Since a lot of airlines do codeshares on these route, just read the search results carefully so you're familiar with the airline selling the ticket and the airline operating the flight because they may be different (example- United will sell you tickets where their alliance partner Air Canada is the operating carrier) and pick some dates and times you feel like are reasonable prices and you can work with.

Good luck dealing with a missed connection or other significant issue while trying to get to your destination in Europe I. much prefer to book with airlines directly and when issues arise, and yes, they arise, I just skip over to the customer service counter while at the airport and fix the problem

No it is not completely like that. The airline I booked with through Expedia also sent me a confirmation. I was able to check in online through there site using the PNR. Also I did have a significant issue last time I booked through Expedia when our flight was canceled; but the agents in person helped us and did not say "oh you booked this through Expedia so call them."

@Jazz+Travels: Can you say with assurance that all major airlines and their customer service agents are willing and able to directly resolve significant issues while you are at interim airports? Any limitations?

Jazz+Travels did say it wasn't "completely like that". It isn't possible to give that kind of guarantee. But the bottom line is you are a ticketed passenger and they need to treat you as such. You do have a choice whether to fly United or Delta. ect. next time so good customer service still matters.

However, for a savings of $700 - $1,000 (booking for two travelers) I personally am willing to put up with a little hassle on the off chance that something goes wrong. That's how much I typically save by booking a package through Travelocity rather than booking a flight directly with the airlines and booking a hotel separately through either the hotel, Travelocity, or some similar site. I've looked and looked and it really is pretty much impossible to book the same trip separately for the Travelocity/Expedia prices.

If you travel a lot and specifically use one airline often (participating in their miles programs) then it makes sense to book directly through the airline for points, or to use points if you have them. But if you are like me and fly only once or twice a year and are staying in the same hotel for the whole trip it is much more economical to use Travelocity or Expedia (I think it's the same company now), etc.

Between the tip from Scott's Cheap Flights and using Travelocity to book my honeymoon trip for a week in London I guarantee I saved a minimum of $1,200 - $1,500 on RT flights (standard economy seats, one reasonable layover each way) and a hotel. The total for two people was around $2,200 for a week in London. That price included a room upgrade (a middling room instead of basic) in a perfectly nice hotel that I have stayed at before, addition of a substantial continental breakfast every morning, and trip insurance. I'm 100% positive I could not have booked the same trip for less any other way because I looked at it about 200 different ways before I booked it.

Kristin, Tim said "Search with whatever tool works best for you. Book on the airline's own website." Amen!! If there is a problem it is much easier to resolve if you have booked directly with the airline.

I guess I don't understand the benefit of using a third party like Expedia or Travelocity vs. booking directly with the airlines? Saving money? Booking a complex ticket that involves more than one airline (so it would be impossible to book it with any single airline)? I suppose if booking on one ticket with multiple connections means "protection" in case of a missed flight (so I don't have to pay to get on a later flight or whatever) might be a good reason.

Otherwise, these booking agencies seem like nothing but a needless middleman.

(But yeah, I like Google Flights too - and it usually directs you to the airline sites so you can book directly with them if you wish.)

Every once in a while, the online travel agencies will get access to bulk or consolidator tickets (think the discount plane tickets attached to some package tours) that the airline doesn't want to sell on their own web sites.

But Seattle-Dublin in September right now is pricing low enough booking directly that I'd just not get caught up in he pursuit of some perfect ticket that might never show up elsewhere, and book what seems to be multiple options for very good tickets right no booked directly with a choice of airlines.

RandomJane mixes apples and oranges. Flights booked through airlines, where the itinerary is available, are usually cheaper than from an on-line travel agency. Hotels booked through agencies are frequently cheaper than the hotels themselves offer. A combo of the two may be cheaper but the customer cannot know until after researching the air and hotel rates separately.
When I say “where the itinerary is available” I refer to a trip combining airlines which do not sell each other's tickets. KLM and Delta, for instance, offer joint bookings. KLM and Air Canada, less likely. That's when I go to an on-line agency, despite expecting further kinks with advance seat selection. My current favorite, despite its tacky name, is Cheapoair because it is easy to use and fairly complete (no site sells everything). I do not expect back-up customer service from any agency. If flights get flummoxed, only the airlines can sort it out, and sometimes only insurance (not bought from the airline) will come through with compensation.
The source with the most listings, courtesy of Google, is matrix.itasoftware.com which does not sell tickets. Preliminary research shows Google's own on-line agency Google Flights does not cover all of the selections in the matrix. In Europe, I recommend www.skyscanner.com for budget one-way flights, which these days include some of the old brand names as well as the widespread discounters. Many do not appear on the matrix or elsewhere.

Simple. Buy from the airline directly. Avoid 3rd parties.

Do use skyscanner or google flights to look for info but buy from the airline's website.

All of my flights to and from London are either on United or Lufthansa operated by United. And I did also try going through United directly but the flights would have cost about the same as the price I paid through Travelocity, but I would have paid significantly more for the room. Do what works for you. I'll keep saving money.

Your best bet from SEATAC will be AerLingus non stop beginning on May 18th.
The alternative would be Icelandair into Kevlavik, Iceland with a connecting flight (after May 8) into Dublin. They often allow stopover for a few days to see their country.

As you can see, there are a lot of opinions on this subject.

What I do is research fares on various sites such as Travelocity, Expedia, Orbitz, etc. They give you a great idea of the flight times and prices.

When you are ready to book, go directly to the airline with whom you wish to book your ticket.

I'm not saying that because of added fees. If there is a problem with your flight, you may have to deal with the online booking agency instead of the airline to resolve this problem. Not every flight has a problem. But if you book directly with the airline, you have 100% control of your travel if changes have to be made (limited to changes based on the fare class you have booked).

I enjoy planning trips and using the internet to research and to save money and time (ie shortest flights fewest stops) on flights and hotels. I have used Kayak, Expedia, Google Flights etc. Sometimes, these services can put together combinations or prices that cannot be matched by booking direct with airline or hotel. We booked an open jaw from Vancouver to Venice and from Rome to Vancouver using Kayak/Expedia which combined flights using Alaska Air and British Air that saved us hundreds of dollars. We could not book the same flights by booking direct with the airlines. I even called my traveler agent friend to see if he could match the booking. When i told him the internet quote, he told me to snap it up. And two of our hotels were cheaper by Expedia than booking direct. The savings add up. I only experienced one problem with a New York hotel which claimed they could not honour a Hotel.com booking and wanted me to pay more. But after complaining to the manager and showing the emails, the hotel honoured the booking. Now, I make a point of sending an email to the hotel to confirm any third party booking.

I would encourage you to head to the tripadvisor travel forum, category:air travel. Read through some of the challenges people have faced when going through 3rd party sites.