Please note that this section relates only to regions, countries and continents, not cities or particular airports.
Microsoft offers with the new Microsoft Flight Simulator 2020 sceneries of incredible quality and the performance is also excellent. Microsoft has a general store called Marketplace where you can find a huge number of additions according to your taste and needs. The company regularly updates the flight simulator and adds, free of charge, new aircrafts, challenges, and other significant improvements to the game.
Another very good company for flight simulation is ORBX . You have the possibility to improve the visual aspect of the simulation by progressively adding layers that offer a higher definition of the territory. Buying a particular region means that many 3D buildings will be included, adding to the realism.
There is also an excellent service. If you have a problem with the installation or anything else, you just post your question on their technical forum and somebody will work on the issue. The company offers the possibility of free downloads for an unlimited period, which includes a full country like Iceland.
MegaSceneryEarth is also an interesting product when it comes to the precise rendering of a whole region, when you fly at a respectable altitude. All the road and houses are included. The weaker aspect is that there is no 3D definition when you start flying at a lower altitude durant the descent for approaches or during the climbing phase. There is no animated persons or animals on the ground, but it’s not the product’s goal. It is then up to you to determine what is your priority when it comes to virtual flight.
For those of you who are specifically interested in France, there is: France VFR
For X-Plane:
There are, among others, FS Elite et X-Plane.Org