FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Color Splash - Convert your images to black and white, then color them selectively.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
JPEGView - JPEGView is a small and fast viewer/editor for JPEG, BMP, PNG, GIF and TIFF images.
GIMP - GIMP is a multiplatform photo manipulation tool.