After spending a few days in Amsterdam, we want to head over to Madrid, Spain and are weighing the plus and minus of trains vs. flights. It looks like discounted flights require extended stops and layovers making what would be a 2 1/2 flight (direct) into an 8-14 hr. nightmare. That's pretty much the length of time it would take a train to make the one-way trip. I would love to hear from anyone who has taken this itinerary and share your recommendations.
See what Air Europa has to offer. They're in both cities.
If you go to Skyscanner http://www.skyscanner.com/, after you do your search, scroll down and look at the left. You'll see "Trip Duration"; slide it to (for instance) a maximum of 5 hours, and you'll limit yourself to nonstops and shorter layovers.
Gregory, I'd suggest having a look at Vueling, which is a Spanish airline. They offer flights from Amsterdam to Madrid, but unfortunately they have a layover of varying durations in Barcelona. The quickest appears to be a departure at 07:00, arriving Madrid at 15:20. There are also flights with Iberia and KLM CityHopper, but they appear to be considerably more expensive or take more time. Travel by train will be about 15 hours with at least two changes. Unless you decide to stop at an intermediate location for a night or two, either way it's going to be a full travel day. One possibility would be to travel by train to Paris for a night or two, and then go to Madrid. Vueling has direct flights departing CDG at 09:40 and arriving MAD at 12:00. Current lowest fare is €89.99 PP. Happy travels!
There is a faster time on Vueling. Depart at 10:05, connect in Barcelona, and arrive at 15:20. As Ed suggested, Air Europa has non-stop flights. You can fly TAP Portugal with a connection in Lisbon.
I'm a big fan of Madrid. But would you consider visiting another enjoyable cultural capital that doesn't require soooo much travel? Antwerp, Hamburg, Cologne come to mind. Another idea would be to see where you can get in an hour on a discount airline from Amsterdam in an hour (after comparing your likely suitcase/backpack size against the luggage fee chart for that airline.)
I can't give airline advice, but if money is an object, or you'd just rather not spend it on airplanes (I don't either), I'd recommend rail. It's frankly more civilized than airplanes. Barely any security, room to move around at your seat, and you can walk around a bit as well as enjoy the scenery and company. A long flight with layovers is torture, but that long a train ride is, to me at least, a little bit enjoyable. As for Madrid, just came from there recently. Get a Madrid Card for the major sights. I was able to get in everything I wanted to see that day because I avoided the lines.
Trains are not a sensible option between Amsterdam and Madrid! It takes AT LEAST 14 hours.
On a leg like that, I'd only train if I was planning multiple stops along the route. The train will waste valuable travel time AND cost more than a budget airline ticket.