Adobe Photoshop is the defacto standard for image manipulation and creation. It's strongest suit is photo manipulation, but it is very good at just about everything else as well. Every serious digital image designer or webdesigner has a copy of Photoshop. It also comes packaged with ImageReady: Adobe's image optimization program for web-bound graphics.

This is a really good 3D modeling program for graphics applications. It doesn't have the many features of AutoCAD for scientific applications, but if you are just making wallpapers this shouldn't be a problem. It is also very well suited for creating animations, so you can make CG movies like Toy Story!

If you can't afford PhotoShop, Paint Shop Pro is a viable, low-cost alternative. It basically copies most of the functionality of PhotoShop and costs 1/6th as much.

This is an extremely feature-rich program for generating fractal images. It can calculate literally any type of fractal and even allows you to write your own formulas. The only downside is that it is limited to 8-bit color and has to run in DOS compatibility mode.

This program also calculates fractals. It isn't as versatile as Fractint, but it supports 32-bit color! :-) This means all your fractals will be nice and smoothly shaded.

Bryce is a simple program for 3D terrain generation. It can make pretty realistic skies and water, but it isn't very good for modeling complex objects. My suggestion is to model cars, planes, etc. in 3D Studio and then import them into Bryce to make the environment.

I use Flash for vector image creation because it works and I don't like Illustrator very much. It's useful for making nicely anti-aliased images that can be easily resized.

Neat Image is a digital filter designed to reduce visible noise and grain in digital photographic images. It is a tool for owners of digital cameras, flatbed and slide scanners; and is for use by both professional photographers, and digital image processing enthusiasts. Neat Image reduces the high ISO noise associated with image sensors in digital cameras and scanners, the film grain visible in scanned slides and negatives, JPEG artifacts of overcompressed images, and color banding. At the same time Neat Image makes images sharper. Neat Image is indispensable in low-light, wedding, sport, and action photography.

AutoStitch is the world's first fully automatic 2D image stitcher. Capable of stitching full view panoramas without any user input whatsoever, AutoStitch is a breakthrough technology for panoramic photography, VR and visualisation applications.

IrfanView is a very fast, small, compact and innovative FREEWARE (for non-commercial use) graphic viewer for Windows 9x/ME/NT/2000/XP/2003.

PhotoFiltre is a complete image retouching program. It allows you to do simple or advanced adjustments to an image and apply a vast range of filters on it. It is simple and intuitive to use, and has an easy learning curve. The toolbar, giving you access to the standard filters with just a few clicks, gives PhotoFiltre a robust look.