Though Thalys does have a monopoly on direct Amsterdam to Paris trains there are two alternate routes not involving Thalys at all.

And here is what I did recently from Paris to avoid the Thalys and excessive supplements with my pass - I took a train from paris-Nord to CDG Airport TGV 2 station and changed to a TGV trains (3 euro seat reservation fee with pass only) to Brussels then an IC train (no reservations possible just hop on to Amsterdam - took two hours longer about but only cost 3 euros above the pass.

So if you want to save a lot of money with your pass consider this route - and the pass will also pay for the CDG Airport to Gare du Nord ticket (but not in reserve from Paris-Nord to the airport for some weird reason).

PalenQ - Thanks. Byron also suggested this as 1 of the options. And after looking at our travel plans etc, we are planning to buy the 5(+1 free) day pass and then use it for AMS to Paris by taking a train from AMS to Brussels and then from Brussels to Paris Airport. We havent yet booked any place to stay in Paris so will then have to commute from Airport to our hotel/hostel that we land up with. Does Brussels station have some place to keep luggage for a few hours? Since we are stopping anyways, we were thinking to explore the area a little bit..

Yes Brussels Midi (a k a Zuid station) does have a luggage storage and you can hop the frequent local trains from Midi to Gare Centraal - the Brussels Central train station, which is really a minor commuter station but a short walk from the Grand' Place and Mannequin Pis - the statue of a pissing boy - the two top things or most famous things to see on a quick tour of Brussels. Be sure you make a booking on the TGV Brussels to Paris Airport as when I did this in reverse there were not many passholder seats available clerk told me - that was left - I'd try to do this in Amsterdam's Schiphol airport International Ticket window which is also the Eurail Aid office - not sure you could do it anywhere else in Holland except at Amsterdam Centraal station's International Ticket Window/Eurail Aide office and there are often very very long lines there. and you have to activate your pass anyway for the two-month period so most easily done at Schiphoil Airport's train station, which also has frequent trains into Amsterdam Centraal. Or for several bucks more than locally have the agent you buy your pass from book that Brussels to CDG TGV to be ironclad - I assume they would do it in Amsterdam but not sure - would do in Brussels but there is a limited number of passholder places on TGVs in France, alas!

the other non-Thalys route would be to take a regional train from Brussels to Lille-Flandres and then hook up with TGVs to Gare du Nord in Paris - could be a bit quicker than the CDG route and it seems little problem for passholders getting on Lille to Paris hourly or so TGVs IME - an option to keep in mind if you have problems getting on a TGV to CDG.

and a third non-Thalys routing would be to take an IC train from Amsterdam to Antwerp - changing there to an IC train to Bruges - spend a few hours in this lovely city that is the consensus for the average tourist the top city in Belgium and then go via regional train to Lille-Flandres and onto Paris-Nord.

Ideally this route stay overnight in Bruges and make it too much shorter rail days.