This image viewer and editor is a longtime Download.com favorite, and with good reason: IrfanView is simple, fast, and free for individual use.
The program lets you make basic edits to images, as well as multiple media formats. You can cut and crop, apply batch conversions, add, sharpen, or blur effects, create panoramas, and change color modes easily. The program continues to add support for an array of file formats and has plug-in support for most image, video, and sound formats, including MP3, AVI, audio CD, and WMA. An IrfanView Thumbnails shortcut on the desktop offers an Explorer-like file tree that quickly displays all images in a particular folder. The latest version even includes a basic drawing palette.
Do note that upon installation, it will attempt to install two Google programs you can opt out of. IrfanView's not going to replace a major paint program, but why use a meat cleaver to cut a stick of butter?