acdsee 5 complete. if you are curious about whether it has a particular feature you want, ask me, and i will try to find it. acdsee has tons of features ( overkill for average users ), but it definetely has everything i want, and i consider myself a power user.
Recently (may still be there), CNET has a face off between ACDSEE and Picasa, I did not read it myself, but you may want to check it out. If you are an Adobe fan, there's the latest Adobe Photoshop Album (about $40 at Amazon), and if you use online photo service, such as Clubphoto, they have freebie photo organize software that you can organize your stuff then directly upload them to their site.