Adobe Photoshop CS5
Cost: $699 - $999
Adobe® Photoshop® CS5 Extended software delivers breakthrough capabilities for superior image selections, image retouching, realistic painting, and 3D extrusions. Experience 64-bit support for fast performance as well as dozens of time-savers throughout your workflow.Artweaver
Cost: Free - 25€
Artweaver is a painting program which is suitable for beginners but also suitable for advanced users. You can record all your steps and replay them afterwards or provide them to other users. Also there are many tools and features like layers and effect filter.Corel Paintshop Photo Pro X3
If creating great pictures is your passion, Corel® PaintShop Photo™ Pro X3 is the photo-editing software for you. Featuring a brand-new RAW Lab and easy batch photo processing, it’s the only advanced photo-editing software to combine photo management, creative projects, photo sharing and even HD video slideshows in one package. It’s everything you need to get professional-looking results you’ll be proud to share. Ideal for DSLR cameras!Gimp 2.6
GIMP is an acronym for GNU Image Manipulation Program. It is a freely distributed program for such tasks as photo retouching, image composition and image authoring.
It has many capabilities. It can be used as a simple paint program, an expert quality photo retouching program, an online batch processing system, a mass production image renderer, an image format converter, etc.Paint.NET
Paint.NET is free image and photo editing software for computers that run Windows. It features an intuitive and innovative user interface with support for layers, unlimited undo, special effects, and a wide variety of useful and powerful tools. An active and growing online community provides friendly help, tutorials, and plugins.