One image viewing/editing app that has some very good features, along with handy navigational elements is
PicaJet FX. The free PicaJet version isn't a slouch either.
Another that I've used for years on end because of its speed and simplicity is
VuePrint. My code is 1531271 if you need to fully test it. I set the Horizontal (F9) and Vertical (F10) column views to 8x8 and hit the keyboard shortcut "T" to display a contact sheet-like page of thumbnails. Or view individually by repeatedly pressing the spacebar. If you work with VuePrint's Configure Options, you can pretty much make it behave however you want. Worth including in the review since many will like it for quick views, especially over Microsoft's Picture Viewer.
Also, not that it can be controlled, but be aware that
ACDSee 8 will be released in the next 2-3 months. It will include video creation (viz., VCD) along with a blog-upload/FTP feature for your photos among other things users have asked for. One clever feature is called a "burn basket," where you can just drag-n-drop photos/folders to a window, and then burn them to a CD/DVD, RAR or ZIP them, or send them via email. The Burn Basket completely eliminates the need for a third-party burning tool, and can also be used to create archives and backups of your files. When you're done, just delete the basket (they're copies anyway).
Pretty awesome.