Excel can open and interpret CSV files on double click.
However, for some locales it may happen that all the content appears in the first row.
This is how I fixed it.
Clean up Preferred Languages
In my case, I am using Excel 2011 for OS X 10.9. The CSV was not interpreted correctly, because German appeared in the Preferred languages of the Language & Region settings.
The simple fix was to remove all preferred languages except from English (United States) so that it would become the primary language, and then re-add the other languages.
After that, Excel 2011 flawlessly opened a comma-separated CSV file on double click and distributed the values correctly over the rows.
German, and other languages, use the comma instead of the dot as decimal separator (e.g. 123,45 instead of 123.45). Thus, Excel on German machines expects semicolons to separate values in a CSV file. The fix above will help to work with CSV files in international environments.