ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Photoscape - high quality photo editing software, that enables you to fix and enhance photos.
Ralpha Image Resizer - High-speed image batch conversion tool
IrfanView - IrfanView ... one of the most popular viewers worldwide.