Acorn is another app you can use FREE or buy the pro version if you need it.
If you used IrfanView in Windows here is a list I did of a comparison between Preview and IrfanView when I first mover to a Mac.
A list of things I copied from the IrfanView web site.
▪ Multi language support -Preview does
▪ Thumbnail/preview option -Preview does
▪ Paint option - to draw lines, circles, arrows, straighten image etc. -Preview Annotates with arrows, boxes, circles and text
▪ Toolbar skins option No
▪ Slideshow (save slideshow as EXE/SCR or burn it to CD) -Preview does slide shows, but to save or burn use iPhoto or iMovie
▪ Show EXIF/IPTC/Comment text in Slideshow/Fulloes etc. -Preview No, iPhoto yes
▪ Support for Adobe Photoshop Filters No
▪ Fast directory view (moving through directory) -Preview does
▪ Batch conversion (with image processing) -Preview does somethings like resize or rotate
▪ Multipage TIF editing Don't know
▪ File search -Preview does
▪ Email option -Preview does
▪ Multimedia player -Preview No, Quicklook yes
▪ Print option -Preview does
▪ Support for embedded color profiles in JPG/TIF -Preview does
▪ Change color depth -Don't kmow
▪ Scan (batch scan) support -Preview does
▪ Cut/crop -Preview does
▪ IPTC editing -Preview does
▪ Effects (Sharpen, Blur, Adobe 8BF, Filter Factory, Filters Unlimited, etc.) -Preview does Sharpen and Color Correction but no Adobe filters
▪ Screen Capturing -Preview does
▪ Extract icons from EXE/DLL/ICLs -No EXE, DLL's or ICL's on a Mac
▪ Lossless JPG rotation -Preview does
▪ Unicode support -Preview ?
▪ Many hotkeys -Preview does
▪ Many command line options -No
▪ Many PlugIns -No
▪ Only one EXE-File, no DLLs, no Shareware messages like "I Agree" or "Evaluation expired" -Preview is only one file, there are no DLLs on a Mac and of course no Nag screens
▪ No registry changes without user action/permission! -No registry on a Mac
▪ and much much more -Preview does PDF's as well