Magnific Popup - The greater part of Lightbox modules will completely preload a picture before showing it.
IrfanView - IrfanView ... one of the most popular viewers worldwide.
jQuery Lightbox - jQuery Lightbox plugins are utilized to showcase images and other web stuff using modal dialogs.
ImageGlass - You can use Image to view your digital images and photos of many different formats.
prettyPhoto - prettyPhoto is a jQuery Lightbox clone.
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!