FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
ACDSee - ACDSee is an image viewer that uses very little system resources, and it has a small, sleek size that won't take up much space on your system.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
digiKam - Professional Photo Management with the Power of Open Source
IrfanView - IrfanView ... one of the most popular viewers worldwide.
Flickr - image and video hosting website