Okay, it's free, enough said.
Seriously, I have used 3 or 4 different photo editing programs through the years. This is by far the best. It does everything I need and more. Sure, Photoshop is out there but seriously, that program is overkill in my opinion.
If you have the right camera, lens and staging know-how, there should be little post processing on your images. The little work they do need, Picasa does easily and effectively.