This post will be updated if I have to add softwares in the list.
All the links in this post are legal links, they are Download.com links or official website links.
unFREEZ (Freeware, really simple to use)
Gif movie gear (Shareware, 30 days trial)
Ulead Gif Animator (Shareware, 15 days trial)
Adobe Photoshop Elements 4 (Shareware, 30 days trial)
PhotoFiltre 6.2 (Freeware)
The GIMP (Freeware, needs to have the GTK+ Runtime Environment installed to work)
Having problems getting used to the ol' Gimp's interface ? Here's an adaptation of Gimp which looks more like Photoshop :
Pixia 3.3 (Freeware)
Adobe Photoshop CS5 (Shareware, 30 days trial)
Macromedia Fireworks MX 2004 (Shareware, 30 days trial)
Paint Shop Pro 10 (Shareware, 30 days trial)
Ulead PhotoImpact 11 (Shareware, 30 days trial)
Pixelr- This is an free online application and its like photoshop