train from Paris to Loire

Point-to-point tickets. Where on the Loire?

If you'll be without a car in the Loire Valley, you're probably best off with a point-to-point train ticket to Amboise. From Amboise there are van tours to some of the more famous chateaux, which are at the eastern end (Chenonceaux, Chambord, Cheverny, Blois, etc.). If you Google "Amboise France van tours to chateaux" you can get an idea of the options.

If you want to rent a car you may need to do it in Tours -- not sure how readily available rental cars are in Amboise, especially if you need an automatic transmission. Do not stay in Tours, though; it's a relatively modern, unscenic city. We stayed in Azay-le-Rideau, which has its own chateau and is an easy half-day trip to Chinon and (in the other direction) Villandry. I can recommend Hotel Biencourt in Azay-le-Rideau.

If you are asking whether a train pass is better because you're thinking of using the train to get from one chateau to another, that is unlikely to work. Most of the chateaux themselves are not near train stations.

Denny,

We stayed in a quiet B&B in Amboise & took a bus to Chateau Chenonceau (my favorite) one day.
We also took another bus from Blois (easy 20 minute train ride from Amboise) which will take you to Chateaux Cheverny & Chambord. Amboise & Blois have their respective castles too.

You can book your train tickets Paris > Amboise > Paris in advance at considerable savings here: http://www.sncf.com/en/passengers

We booked the direct Intercity train from Paris AUSTERLITZ to Amboise for €15 pp each way.

Have a wonderful trip!

There is a direct train from Paris to Tours, about 20 min drive from Amboise. I don't know if there is one to Amboise.

Chateau's in the Loire are scattered about. A car is advisable, though tourist offices in Amboise, and likely Tours, can put you in touch with bus tours to the some of the major chateau's. The Amboise tourist office is very helpful with this.

Note that it is not possible to rent a car on Sunday in Tours or Amboise. In Amboise, cars can be rented though the rental office is on the outskirts of town. Getting there requires a car! Their service is Europcar, I think.

Have fun,
Ed

Regarding this comment from Ed:

There is a direct train from Paris to Tours, about 20 min drive from Amboise. I don't know if there is one to Amboise.

There are a couple of direct INTERCITÉS (Intercity) trains departing from Paris Austerlitz station & arriving in Amboise.
Most other options include 1 change, either at Saint Pierre des Corps in Tours, if departing from Paris MONTPARNASSE station, or in Orleans Centre, if departing from Paris Austerlitz station.

If you want to visit a few chateaux, you don't necessarily need to rent a car.

If you need more information about the public bus that takes you from Amboise to Chateau Chenonceau & the bus that you can take right in front of the Blois train station (€6pp), that takes you to Chambord, Cheverny & Beauregard Chateaux, you may find this information in RS France book, or you can send me a PM for details.
Please note: The bus from Blois (to the chateaux mention above), only runs on Wednesdays, Saturdays & Sundays.

Have a wonderful trip!

I'm heading from Paris to Bordeaux and was thinking of an over night stop somewhere in the Loire.

Any suggestions for a quick stop like that? What city has the best combination between train access and easy chateau to see?

Stephen - Tours, Blois, and Amboise have pretty easy train connections from Paris and to Bordeaux. Tours is a faster train connection with direct trains both ways. Amboise and Blois are still pretty easy train connections but trains to Bordeaux from either transfer in Tours, so there is that added minor inconvenience. All three offer 1/2 day and whole day tours to various chateaux. My vote for best place to overnight (based on my own preference for town size and quaintness (word?)) would be: 1. Amboise, 2. Blois, 3 Tours. I stayed in Azay-le-Rideau and I loved it, but I had a car. Connections from Paris and to Bordeaux are possible but, again, involve train changes. Azay in the evening with the chateau flood lit was marvelous to walk around and it's quite small compared to the others.