[skrtja]

Upgrade from GIMP! Photoshop is a good place to start, but Lightroom is more for editing photos after shooting and Illustrator would be more for commercial uses I presume according to @mothered . Depends on what you what to edit. If you want to add objects and remove backgrounds and add scenery then Photoshop. If you want to tune images then Lightroom and Illustrator for that commercial edge I presume.