Travel from London to Amsterdam

If you book in advance the cheapest would be EasyJet from London Gatwick or Stansted or Luton. It's also feasible to do this by train: Eurostar from St Pancras station to Brussels. At Brussels transfer to the Thalys high-speed train to Amsterdam. Train will be a bit more expensive, but will be more comfortable and when you take into consideration traveling to/from the airport, and airport security....won't take much longer.

Rather than taking the Eurostar from London to Brussels and a Thalys train from there to Amsterdam, you can take the Eurostar to Brussels and an IC train from there to Amsterdam. The ride takes an hour longer, but you can get a fare as low as €50 for the entire route by booking at NS Hispeed. Besides, no reservations are possible on IC trains so you could stop over in Brussels for a few hours and then continue on to Amsterdam on any IC train. Book up to 120 days in advance to have the best chance of getting the €50 fare.

Another option is to take the train-ferry-train combo known as the dutchflyer. You can travel during the day or overnight. It costs a little more for a cabin on the overnight ferry, but you save the cost of a night in a hotel and you have more daylight hours for sightseeing.

This is great information, because we are thinking of going to Amsterdam instead of Germany.

I don't necessarily want the cheapest way, so the idea of going by Eurostar is very appealing.

For what it's worth -- we were thinking of flying from Amsterdam to London on our upcoming trip, but looking at the fares on NS-Hispeed, we decided to train it via Brussels instead.

It might take a little longer, but also seems more comfortable, drops us off at a more convenient location in London, and it actually might be cheaper! easyJet would've been 35EUR + booking fees (4EUR), VISA fee (almost 10EUR), and possible luggage fee. Trains would be 50-70EUR.

Oh, and we get a tiny stop-over in Brussels, which is nice, since we didn't have time to otherwise fit it in on this trip.

We'll be doing this in July. I booked a flight from Gatwick on Easyject for $50Cdn each. Flight is about an hour.