I might be biased being Swiss, albeit from the German speaking part, but the French part of Switzerland seems like perfect fit for your requirements. You both speak French, your kids will get high quality education for free and eventually access to two of the world leading Universities (no getting in debt to get an education, but that will hold for the most of Europe, too). There's lots of natural beauty, especially Lausanne is a wonderful city and Geneva is consistently ranked amongst the top liveable cities. Compared to France, which was also mentioned here and is definitely also a great place to raise children, it has lower crime rate and way higher salaries.