Branching out from Paris

What are you looking for? Strasbourg, Lyon and Bordeaux are all worth a visit and within 2 hours from Paris by train.

Do you want to stay 4-5 days in one place, or move around, say, 2 nights in each place? Also, how far outside Paris is "outside" for you?

There's always Versailles, with Rambouillet farther out on the same train line. From Rambouillet you can go onward to Chartres. If I'm not mistaken, that train route goes through Maintenon. This region of France would be fun if you're interested in the history of the Louis kings in the 17th and 18th centuries. IMO Chartres itself is a lovely, walkable town with a pleasant "old quarter."

Of course, many/most people visit Versailles as a day trip from Paris -- and Chartres also works as a day trip -- but I've found it impossible to really see and appreciate the entire Versailles palace and grounds in a day trip. If I ever get to go again, I'd love to stay at least one night in Versailles so I could spend two full days on the ground there. The Hotel Ibis near the train station seemed very nice; we ate breakfast there before touring the palace, and came back for a late lunch before returning to Paris.

Amboise - should be well covered in RS books. Easy train ride and hotels a short walk from the station. You can join a group mini-bus tour to visit Loire Valley chateaux.

Chartes is an easy day trip from Paris to visit the cathedral.

There are a ton of great day trips from Paris within about an hour by train many of them will be covered in your Navigo Decouverte travel pass (it covers all of the Ile de france -- so places like Versailles, Vaux le Vicomte, Fountainbleau, Provins, Moret sur Loing, Crecy la Chapelle, St Germaine en Laye. etc etc. And a few others that require train tickets e.g. Giverny, or Auvers sur Oise.

For two night or more side trips. Lyon would be a great choice -- get a tour of the traboulles. Strasbourg would be good fro 2-4 days with side trips in region. We did 4 nights in St. Malo and then did trips by bus in the area -- it was fantastic. This last trip we did a 4 night trip to Annecy and a day trip while there to Chamonix for the Aguile du Midi (we waited till the weather report was clear and then booked bus and trip up the mountain the day before)

Hi,

Can I add Reims (where I was earlier this week), Lyon (also there this past week), Strasbourg, Caen, Beaune, and Colmar?

Lyon is two hours away via TGV and you can easily spend three to four days there and not be bored. It is exceptional, in my view.
Reims is worth only one full day, unless you are a HUGE champagne fan. It is 48 minutes away, via TGV but I found a day trip from Paris was fine. As of this week, the Porte de Mars, the Musee de Beau Artes, and the Palais de Tao (sp.?) were all closed and under construction, so plan accordingly.
Similarly, Beaune is worth only a day trip, unless you're a wine fan (which I am), at which point 3-4 days are great. A day trip is fine to see the sights within the City itself, but if you like wine, you're going to want to bike into the vineyards, take the train to several stops along the Cote de Beaune or take various wine tours.
Similarly, Colmar and Strasbourg are reachable, but they are within the Alsace region and if you enjoy mountain views, great white wines, and biking, an extra day or two cannot hurt. I particularly like the Petite Venice.
Finally, I really liked Caen: there is a great WW II War Memorial Museum, and from there you take a tour of the D-Day beaches or rent a car and hit Mt. St. Michel.

As others have noted, all of the above are achievable and worth your time. You should decide, and perhaps disclose here on the blog, what your "interests" are, as all are very enjoyable and walkable.
Best of luck,