Unfortunately I had the bright idea to go to Brussels on a daytrip from Paris well after I planned the rest of the trip and by the time I booked all of the lower fares were gone. THALYS tickets are sold in a similar manner to Eurostar tickets, there are different tiers of fares and once a tier is gone seats on that train bump up to the next fare. Tickets seem to start at 22€ one way if you book well in advance, by the time I figured out I wanted to go there, there were some extremely inconvenient 29€ fares, some still too early 39€ fares and 49€ fares that were manageable and several trains that didn't have the non flexible rate anymore.
Some people report problems using US credit cards on the THALYS site, I used http://www.b-europe.com/ which is still affiliated with THALYS and had the same trains with the same prices. Rail Europe is more expensive but another option if your credit card doesn't work.
The train was a comfortable fast train, it takes you from Gare du Nord in Paris to Brussels Midi, from there you can use your Thalys ticket to get to and from the Central station as there's nothing of interest near the Midi station and some sources said it was a little seedy.
It is great traveling from Holland to Paris by train (Thalys). Remember one thing, your tickets are reserved for a specific train. We took one train earlier without knowing this, so half way we were check and apperently we were in the wrong train. "Mais je ne sais pas, hein?"
The Thalys train offers promotions from 25 EUR each way from Cologneif you book a couple of weeks ahead. Normal prices are 90 EUR each way. Duration is 3h45Min - arrival straight at Gare Du Nord from where you have a convenient Metro connection to everywhere in Paris.
The Thalys train has a monopoly on the trains between Belgium->Paris. You can get some pretty good discounts if you buy a round [return] trip ticket, but [at least last September] there were no discounts for one-way tickets.
After doing some research, instead of taking the Thalys Antwerp->Paris Gare du Nord train, we did this:
Antwerp->Brussels Midi->Charles De Gaulle Airport via TGV, then RER into Paris Chatelet.
It requires train changes, but taking this instead of the Thalys saved us $50 each. It took about 35-40 minutes longer to get to central Paris,
However as you can see below, that was trimmed to about 20 minutes because the RER goes deeper into the center.
From Paris Nord [terminus of the Thalys], it takes about 22 minutes by metro/bus to get to the Marais neighborhood of our hotel.
The RER does stop at Gare du Nord, but by getting off at the next stop (Chatelet), getting to the Marais was just a 7 minute ride on the 69 bus. So, you actually get about 15 minutes back.
The savings paid for our 2-day Paris Museum passes, so we thought it was well worth it.
My husband and i travelled from Brussels to Paris just last month by the thalys....it hardly takes an hour and a half.I think its the best n fastest way to travel between these cities.If flying is your other option,the time you take to check in and check out will leave you with little or no advantage over the train!but you have to reserve the tickets in advance.you even get a meal if you are travelling first class:)
From Brussels to Paris, an ideal way of transport, relativaly cheap and fast - it will take about 90 minutes to reach the city of lights
Negative : the welcoming "BF" bar at wagon 4 is unprofessional organised, problems to get a free space, making a long queu, the tenders have no money change or even the official menu list is limited. Better take yr own food on board - the trip is short
thalys has a good offer on at the moment. i went to paris and back from cologne (koln) for 80 euros. discounts for those under 26. it took just over 3 hours and was a comfortable journey. no smoking however! stops koln, aachen, liege, brussels central and paris.