One night in Paris, take the taxi?

While I haven't taken a taxi in Paris, I imagine it would be fairly easy. However, based on my experience using the Metro and RER, I don't think you'll save any time taking a taxi. In central Paris you're never more than about a five-minute walk from a Metro station. It may take you longer than that to find a taxi rank or to flag down an available taxi that is passing by.

Fares may go up on 1 July, but as of today you can buy a carnet of ten t+ tickets for €11.10 that are good anywhere the Metro goes (some lines end in zone 3), on the RER in zone 1, on buses, and on the Montmartre funiculaire. Each ticket allows unlimited transfers on the Metro and/or RER until you exit the system. Each ticket is good for bus-to-bus transfers up to 90 minutes after boarding the first bus. Share the tickets in the carnet with your wife.

After a day or two in London, you'll be old pros at using the Tube. The Paris Metro is just as easy to navigate, even if you don't speak French. The direction each train is going is indicated by the last stop at the end of the line. When transferring, follow the "correspondance" (connection) signs.

See this zoomable map of the Metro & RER system.

Still, walking in Paris is marvelous so be sure to do plenty of it!

The Metro is much more convenient and you will save lots of money. It's a really easy system to figure out and it will get you anywhere you want to go. I would suggest to forget the taxi.

If you happen upon a taxi stand and can hop in one, I'd do it to save time. Be sure you can tell the driver the location or street you want to go to. I have also managed to flag a taxi down, around 9:00 pm in January in front of the Eiffel Tower -- but it wasn't easy! Otherwise as others have said, if you are near a metro, take that, but study a map before hand to know what train to take. It just depends on how much time you have.

I was in Paris a few weeks ago and tired and decided to take a taxi from the train station to my hotel because of the luggage issue. I was so ripped off. The hotel and other taxi driver's told me that I had been scammed and did I get a receipt or the number of the taxi....I had not. I waited in the line of departing passengers from the train and got the taxi from the "real" taxi line but, I was still taken advantage of. The metro is so very, very efficient and easy to use. If you do take a taxi, ask about how much before you get in and if you feel you are being treated unfairly do not get out of the taxi until the driver gives you a receipt. Not that anything would actually be done about it but, you could at least complain about a particular driver. I would have to be really in need to take a chance of a Paris taxi again!

A lot of the usual must see sites are within walking distance and you are enjoying the beauty of the city as you go. As Rick says most sites are within 5 blocks of the Seine.