The first stage of planning, and already my head is whirling =)
We are flying into Madrid and Kayak, SkyScanner, and Bing Travel are all finding the best prices on JustFly.com and Hop2.com and so they are redirecting to those sites. Both, based on what research I'm able to do, sound like websites I would not want to book through. Rather than try to research each of the 30+ such websites that these search engines pull up, I thought it better to ask people with experience if there are websites that are known to be good and reliable, or what kind of approach (do you just take the best price / itinerary combination off of a site like Kayak without a second thought? Go through particular vendors like Orbitz? Go directly to the airline website?) people who have experience have used that have been consistently reliable.