Photo Ninja is quite impressive.
Do you have any examples or comparisons to share?
I'm using Lightroom. I loved version 3 and version 4 is just insanely impressive. The processing is great but I also like the organizational tools - I was really never a big fan of Adobe Bridge.
My one complaint with Lightroom is speed. I have an Intel i7 930 @ 3.5 Ghz and 18GB of RAM and Lightroom is far from being snappy when I'm trying to browse a large catalog of 18 MP RAW Files.