savegame - In which directory to write game save files/data?

I need a definite list of directories, one or more per platform, of where to put game save files and other game generated data. Either based on the OS developer specification, or because it is common usage if there is no recommendation.

Please provide one answer per platform, with different directories. Also, example of how to get the directory location in C++ or C is best, as it's the language you'll have more hard time.

Locations:

• Player's game data (saved games, config).


• Shared game data (like high-score or config for all computer users).


• Temporary game data (aka cache directory).