I’ve been using the GIMP image editor (also known as the GNU Image Manipulation Program) (also known as the wonderful, open source, free photo editor with the awful name) a lot lately. Version 2.4.2. I highly recommend a second look if you haven’t tried it recently. The newest version has vastly improved controls for cropping and selections, a foreground selection tool, a healing tool, and better brush management among other enhancements.
But one thing my stock GIMP install didn’t have was a decent noise removal filter. That is, until I downloaded and installed the GREYCstoration plugin. Installing it is as simple as downloading and dropping the plugin into the GIMP plugins directory. Restart GIMP and you’ll find a new menu under Filters | Enhance | GREYCstoration.