JPEGView - JPEGView is a small and fast viewer/editor for JPEG, BMP, PNG, GIF and TIFF images.
ImageGlass - You can use Image to view your digital images and photos of many different formats.
FreeVimager - Free & Fast Image Viewer and Editor for Windows.
Fragment - A powerful image viewing suite with advanced metadata info
Phiewer - Image Viewer - Phiewer is the easiest and fastest way to view your images, videos and even audio files.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.