Formerly a commercial product, but now free for personal use, BonAView is a capable and attractive image organiser with plenty of features.
You're able to browse your images in 3D space, for instance (see the grab). Which looks good, even if it's not the most practical way to visually scan a large photo collection.
More usefully, you can organise your photos in a custom set of categories which can be as complex as you like. And unlike some similar tools, BonAView allows you to build up your database with unlimited categories and subcategories, so it's easy to bring order to even the largest of photo collections.
Of course you'll still lose track of images occasionally, but the program's search tool enables you to look for images by their file name, size, type, image dimensions, rating, "last modified" date and so on.
Once you've located a particular shot then you're able to tweak its colour or brightness, remove redeye, crop, resample, or apply various filters and effects. You can rate the photo, change its category or view and edit its EXIF and IPTC tags. And the annotation module is powerful enough to justify installing BonAView all on its own, delivering options to annotate your images with watermarks, captions and more.