Image files organizer for OS X
I use Adobe Bridge, which comes with lots of Adobe apps (list, starting at $250).
It does all you want, and a lot of other stuff too.

Some of my favorite features, other than those that you mentioned:


Full-screen previews
Powerful batch renaming
Cache export
Configurability / flexibility
Speed


Another option is Adobe Lightroom ($250). It combines a Bridge-like manager with a reasonably-powerful editor.



I realize that Bridge and Lightroom certainly aren't free, but Bridge really is my favorite image manager.
If you want something that's free, the built-in iPhoto app is a good option, although it's far less powerful. It's got some nice features like face recognition and location-based sorting.