FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
Retrobatch - Retrobatch is a unique application for automating actions to tens, hundreds, and even thousands of images at the same time
digiKam - Professional Photo Management with the Power of Open Source
ImageGlass - You can use Image to view your digital images and photos of many different formats.
FastPictureViewer - A hardware-accelerated image viewer for the modern Windows platform.
AYVY - JPEG/PNG/RAW Images viewer