My husband and I and our three girls will be flying from Brussels to Geneva in July. I actually have two cars reserved right now - one on the French side and then a (surprisingly) cheaper (well, less expensive) one on the Swiss side. Does it matter where we're headed? I intially selected "French side" because we were heading in that direction - we'll be driving to Chamonix for three nights. Does it matter from which side we rent? Of course, I'd like to keep the less expensive, Swiss side rental and cancel the French side one. Thanks!
What usually matters is where you will return it. If the rental is roundtrip to the same airport, then choose whichever is cheaper. If you'll drop in another city, then you want the country to match to avoid 2nd-country drop off fees. But either way, you can easily drive between those neighboring countries.
If you rent from a French firm and plan to drive in Switzerland, make sure the rental is provided with the highway tax vignette (fines if you're caught without one).
Yes, the Swiss Vignette will automatically be included on the car if you rent from the Swiss side.
It depends on where you want to drop the car, there is a huge fee to drop off in a different country.
Inside the airport there is an easy walk via a long corridor but the drive around to the French side was a bit obscure.
Enjoy the trip!
I've rented at Geneva airport several times, always on the French side. We were only going to be in France in each case, and renting from the French side was cheaper. But, as others have mentioned, a key factor is where you'll be returning the car. If it's elsewhere in France, then rent from the French side. The vignette, too, can be an issue. We just avoided driving on the Swiss motorways.