Paint.NET: Excellent photo program!
IrfanView: Graphics viewer and converter
GIMP: Full feature image editing program with the ability to import and edit PhotoShop files (PSDs)
FileZilla: NOTE: While this is an excellent free FTP program, the main installer carries serious malware. Use our link here to install, not their website!
Pixie: A handy little tool that will give you the RGB, HTML, CMYK and HSV values of any colour you see on your computer. Simply run it, hover over the colour you want and copy the values you need.
Notepad2: A fast, light-weight text editor with syntax highlighting.
Programmer's File Editor: While it does not have the syntax highlighting that Notepad2 does, it will conveniently strip out all of those pesky forbidden characters that come with standard word processors.