Transport from Paris CDG airport to Paris central

A taxi will cost 45 - 50 Euros. Here's one good article.

We took the RER train from the airport into Paris, It was very easy - I don't reacll the cost but I THINK about 8 euros each (there were 3 of us).

Stephanie:
I strongly advise you to forget the expensive taxi and take the RER train right from CDG to Gare du Nord. From that central station, there are all sorts of subway lines to where you want to get. Use the saved money for a great meal and bottle of wine. Of course, this assumes that you have packed reasonably light, and have suitcaes with wheels.

You might also want to check out Page 436 of Rick Steves Paris 2009 guide book for advice on traveling into the city from the airports.

If there are three of you, I am not as sure as others that the RER is saving you that much money. It's going to cost more with a taxi, but not dramatically more. And of course a lot depends on how much you are packing.

I do the RER with my one rolling suitcase, but if I had a lot of stuff then I would not do it!

A taxi would be ever so slightly easier. However, I would never pay for one, as a matter of principle. I believe the RER costs 8/person, and I have to think a taxi would be easily twice as much. Taxi takes around 45 min, RER is 35-40. Of course, if you use the RER, you will be forced to figure out the Paris Metro, which is, of course, comically easy.

If you're packing light, I also would recommend taking the RER and Metro. For detailed instructions, including photos, go to Parisbytrain. The current fare is €8.40 and includes unlimited transfers to the Metro and/or other RER lines until you exit the system, thus getting you to within a few blocks of any hotel in Paris.

According to the Aeroports de Paris site, the average cost for a taxi to central Paris is €50, but the meter will be running so the actual fare will depend upon traffic conditions.