When going to Venice, departing from Sion or Brig?

If you are choosing between Sion or Brig, I would choose Sion. It has a wonderful, medieval town core with two hills in the middle - one topped by an old castle and the other with one of the most well-preserved medieval churches in Europe. The oldest organ in Europe is still played there! Sion is a very "real" town with a lively, family atmosphere. The whole valley around it is surrounded by beautiful terraced vineyards that have been there since the time of the Romans.
There really isn't much to see in Brig - it serves more as a gateway to Zermatt since it's at the base of the valley that goes up into the mountains.

Say NO to the car. You don't need it or want it. Your 12 year old son will travel free with you with a Free Swiss Family Card which you can get if you buy some sort of Swiss Pass product for you and your wife. Of your choice of Swiss Destinations Geneva is the least interesting as a tourist. With only 5 nights you need to concentrate on Lauterbrunnen (Jungfraujoch) and Lucerne. That's all you have time for. There will be MORE than enough to keep your family busy and abundantly happy in those destinations.

If your plans include the expensive Jungfraujoch then you absolutely need at least a Swiss Half Fare Card. The savings on that trip alone (50%) will pay for the HFC and your son will go absolutely free.

You sound as if you may be new to the Europe scene and since you're traveling onward to Venice I just want to make sure you know the difference between Venice Island and Venice Mestre. Mestre is the industrial town on the mainland. Hotels are cheaper, nothing to see there, and you'll have to train to Venice Island everyday and back. Don't do this. Choose a hotel on Venice Island and train directly into Venice Santa Lucia railyway station.

Hi Anita, thank you for your comment. I see that Sion is a more attractive city than Brig. I've also found that there are so many things to see around Sion. I'll spend a night there before going to Venice.

Hi Tim, thank you for your suggestions as well. Yes, I know that car is not really necessary. I've researched enough, however, and found "The Grand Tour of Switzerland" very attractive. Although I can't visit all the places on The Grand Tour, I can at least visit some places.

By the way, why don't you give me your opinion on my question - Sion or Brig. ^^

For Geneva, I want to visit Reformation Museum and St. Peter's Church where John Calvin preached as well as Palace of Nations (UN). I also want to visit Olympic Museum in Lausanne. To meet the end, I think I need a car to move quickly. I will have enough trains with TGV, Euro City, Italo and Trenitalia as well as Jungfrahbahn. Have you seen The Grand Tour of Switzerland? There are so many beautiful places in Switzerland. My 5 days are too short...

For Venice, yes, definitely will I go to the Venice Island instead of Mastre. Any hotel recommendation?

For getting around Lake Geneva I really would recommend using the train. The main highway going out of Geneva, that runs around the north side of the lake, can be very congested and the train is much faster. It has taken me almost 90 minutes to get from Vevey (just near Lausanne) to Geneva by car - the train is half that time and much more pleasant. Parking in towns in Switzerland can be difficult sometimes, especially around Lake Geneva where things are quite compact.

Thank you, Anita, for another helpful comment.

If it's not convenient to drive near Lausanne, where should I rent the vehicle? Any suggestions? I really want to drive on Susten Pass, Grimsel Pass or Furka Pass or on two or all of them.

You could drive all three passes in a day trip from any base in the area (e.g., Interlaken, Brig, Lucerne).

What month will you be traveling? The month will make a huge difference in those passes.

The Swiss trains are quite amazing. After you have ridden them for a while you may very well decide that you would have liked the whole trip to have been on them. The windows are big, clean, and the seats are very comfortable. The trains go places cars can't.

That said, I drive in Switzerland pretty much every year - my windscreen is absolutely covered in Swiss and Austrian Vignette stickers - but that is pretty much because it is a driving holiday with my own car which I drive over from England. Most of the time it winds up parked because it is so much easier and more beautiful on the trains. The train between Interlaken and Luzern via the Brunig Pass is great. On the narrow gauge rack for much of the journey because it is so steep, that route goes through the trees, past glacier lakes and with views of dozens of waterfalls; and stops and turns around in Meiringen, the home of meringue and the Reichenbach Falls (you can climb up them) where Sherlock Holmes and his arch nemesis Moriarty had their fatal encounter.

You can take Postbusses over the passes you want to drive so that you can enjoy the view and not have to navigate all the hairpins looking at the road instead of the scenery.

Between Sion and Brig - where are you returning the car? That will make a difference.

Many more trains from all points stop in Brig than Sion. Sion has a nicer town. I don't know if either have car rental places, or what hours they would be open.

There is a Europecar rental office right in the rail station in Sion. I just happened to notice it when we were there last time. Hertz has an office in Sion as well but I'm not sure where it is in relation to the station. We personally love driving in Switzerland...the trains and buses are fabulous but I like the freedom of not having to stick to any schedule but my own and turn off onto little roads to see where they go!

Sion has a Hertz location that is about 10 minutes away from the rail station by foot. But there's no Hertz location in Brig. The reason why I want to go with Hertz is simply because it has a great offer for a weekly rate (pay now though). It doesn't matter where you pick up and return the car.

And by the way, for a car, does it have to be strong enough to drive on hilly roads and mountains in Switzerland? Or is a small car (compact or midsize) okay?

I've used everything from a Volvo SUV to something called a "Twingo" (I think that was the name) which was very small, and they have all worked fine. You may not get to the top fast and be passed by everyone else on the way up but a compact car should be fine if you are comfortable driving one. With how narrow some of the roads can be, I prefer a smaller car!