SageThumbs - SageThumbs is a powerful shell extension allowing to preview enormous amount of image formats...
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Icaros - Icaros is a collection of lightweight, high quality, Windows Shell Extensions
IrfanView - IrfanView ... one of the most popular viewers worldwide.
FastPreview - FastPreview was created in need of a usable ...
Seer - A Windows Quick Look Tool in Qt.