You can reach some of the larger towns in Switzerland by TGV... We enjoyed exploring Basel and Lucerne.
Or, since you like Amsterdam, you could stay over at a couple of other Dutch towns such as Delft and Alkmaar...

If you want to keep the travel down then look at one of Luxembourg, Trier, Reims or Strasbourg. Each has interesting centres, some fine hotels and good wine. Trier (probably the least famous of the four) was the capital of the Roman empire for 30 years or so. Luxembourg/Trier could be done as a day trip from the other.

Loire Valley, definitely.

Why not check out Bruge or Brussels.Its a quick train ride

List of suggestions can be long. Both Paris airports (CDG & ORY) are served by a number of discount carriers that can reach lots of worthy European destinations in 60 to 90 min. Check Easyjet & Vueling for list of direct flights. French rail SNCF http://www.voyages-sncf.com has sales all the time. In a slightly over an hour you get to Brussels, 3+ hrs to Amsterdam & Geneva, Marseille, Bordeaux, etc

I'd hesitate to go to Normandy in March. It can be very rainy and windy there.

Have you been to the French Riviera? Nice is a very interesting city; it has a lazy sensual vibe with its blending of French and Italian cultures, Belle Epoque architecture, interesting cuisine, art museums, market. (Can't speak to the nightlife.) And Nice makes a great base for daytrips by public transportation, along the coast and inland.

Another thought is Berlin. Lots going on there in architecture, art, nightlife. I'm not so sure how you'd feel about German cuisine.

Out in left field, Istanbul is probably too long a trip for you, but it's a less than 4 hour flight. A very vibrant city in a beautiful setting, with great food and nightlife, interesting architecture.

I think, considering the time of year, that I would choose Madrid. Normandy and the Loire are both beautiful in the spring and summer but unlikely to be pleasant in early March. If you are crowd and tourist averse and want to see Venice, that also would be good in March.

I would do Normandy in a heartbeat. Or the Loire.

Thank you everybody for the replies. "Unfortunately", I have been fortunate enough to have been to most of the places places mentioned. The Bruges and Brussels idea is such a good one that I did it on my last trip to Paris; rented a car and went to Bruges and Brussels, and drove around Belgium and Germany a little.

The French Riviera is a great idea too, though I've been a few times, I have not been in a few years. I was also thinking about Marseilles, a city about which I know nothing.

In any event, I have some good suggestions here; thank you. Time to do a little research and some thinking.

Well, I think your original idea is a good one. Amsterdam.

Venice: let's face it; it is more complicated than most places, but really worth it.

Amsterdam and Marseilles would be interesting. Madrid is a good idea, also, for several days. I'd much rather go to any of them rather than Normandy or the Loire in March. Nice isn't a bad idea, either. I was just in Madrid several months ago and the current economic climate is no reason not to go at all. I was even there during some huge protest and it didn't bother me, and I haven't actually heard too much about those lately. Several days in Madrid is a good introduction to the city and they have terrific museums. It would be a good contrast.

Check out Easyjet for where they fly from Paris, you'd be surprised. YOu could easily go to/from Krakow, Prague or Budapest that way, I know, as I've been checking. Or Berlin even easier as they fly in/out of Orly.

For a vibrant city with nightlife, great food and interesting architecture,
Madrid would be my choice. We were there end of Oct....no problems.
Berlin is also a great city, but the weather in March could be miserable.

Er kinda obvious, so will assume you have been numerous times, but what about London, 2.5 hrs city center to city center, then stay a few days and do some daytrips from there..

I also agree that going in March would make me think south too( heck I was in London in March one year and it was sleeting and raining and freezing, yuck). Spain is a great idea and flights are less then 2 hours, so even with "airport" travel time etc its still reasonable. It won't be hot in March but doubt it will snow or sleet!!

Back to Venice, Easyjet flies from Orly (easy to get to) to Venice. The flight's less than 2 hours. And it's not so hard to get into Venice. In fact, it's part of the experience. You can spring for a water taxi from the airport or take the bus to Piazzale Roma and catch the vaporetto.

Architecturally, Venice is very interesting, with the eastern influence: onion domes on the duomo, abstract patterns on house walls. They manage to make those palazzos along the canals appear to float on the water. It's all to easy to build a building at the water's edge that looks like it's half-sunk.

And you could do a Palladio excursion one day if you have time.

You have to see Venice before it sinks! Or rather before the sea level rises due to global warming.

Venice [because you should see it again, and who knows who you might meet there] or Nice, because it's, well, nice!

are you flying into and out of Paris?

if so you can do both:

if so, you could fly to Venice, and then to Nice [easyjet] and either fly or take TGV back to Paris.

or the other way round.

Thank you for all the great responses. I am still undecided, but Amsterdam certainly seems like the easiest, most practical getaway. But Madrid and Venice are still considerations, for reasons enumerated above.

I think I will see how Paris is going for me, and if I desire to spend more days away from Paris, I'll go to Madrid; if I want to just do a "weekend" away, I'll do Amsterdam.

And yes, London was one of my first ideas, but as you mentioned, I have been quite a few times, and I have no need or burning desire to go at this time.

What a wonderful predicament you’ve found yourself in I’ve not been to Amsterdam so can’t comment, but I have been to Madrid and loved it even more than Barcelona – it feels so much more local. There’s a really great article on what to do in the city if you’re travelling solo on this website: http://www.cstn.org/reports/europe/spain/spainmadrid02.html

As for your other options, have you thought about Verona instead of Venice? Cheaper and in my opinion more beautiful, much better food and you can still day trip out to Venice. I also spent three months living in the Loire from Jan to April and would say March is perfect timing – first blush of spring but before the tourists have set in. I’d highly recommend a beautiful village called Montsoreau, next door to Saumur and only a couple of hours away by train from Paris. The cheese and local sparkling wine are to die for if that’s your thing.

I could go on! Message me if you want more tips on any of the above. Happy travels.

What happened to Normandy and Loire?

Yes, a horrible predicament. I have decided to not fully decide. My tentative plan is to go to Amsterdam, because it involves a train ride and not a flight, and the associated time and inconvenience that goes with that. Madrid is definitely still a possibility, as is Venice, though Venice is less likely due to the time/expense/travel logistics.

The Loire and Normandy are still definite possibilities as well, though I am much more likely to do this if my traveling companion extends her trip by a few days, and I would rather not do this alone.