Some IrfanView features:

• Many supported file formats
• Multi language support
• Thumbnail/preview option
• Slideshow (save slideshow as EXE/SCR or burn it to CD)
• Show EXIF/IPTC/Comment text in Slideshow/Fullscreen etc.
• Support for Adobe Photoshop Filters
• Fast directory view (moving through directory)
• Batch conversion (with image processing)
• Multipage TIF editing
• File search
• Email option
• Multimedia player
• Print option
• Change color depth
• Scan (batch scan) support
• Cut/crop
• IPTC editing
• Effects (Sharpen, Blur, Adobe 8BF, Filter Factory, Filters Unlimited, etc.)
• Capturing
• Extract icons from EXE/DLL/ICLs
• Lossless JPG rotation
• Many hotkeys
• Many command line options
• Many PlugIns
• Only one EXE-File, no DLLs, no Shareware messages like "I Agree" or "Evaluation expired"
• No registry changes without user action/permission!
• and much much more