And you have 401 categories/subcategories which my calculator says is averaging over 872 listings in each category....ouch...so much for user friendly...hehe (please take that as constructive criticism).
The problem I see right off the bat is that you have several Topical categories, which should be subcategories of other Topical categories and subcategories (Gifts & Flowers, Food & Drinks, Fashion, Pet supplies etcetera look like Shopping to me, but I could be wrong). Things like:
-- Healthcare ----------------------------
Plastic / Reconstructive Surgery
should be listed as a subcategory of Health & Beauty and shopping sites/stores should be under a Health & Beauty category of Shopping etcetera.
You need to sort out all sites /listings that are stores/shopping and get them under Shopping and sort out all "informative" sites into proper "informational" topical categories, then crosslink/@link the information categories with their respective shopping categories and visa-versa.
With that many listings and that broad of a directory (without getting into regional categorization) you will probably have literally 1000's of categories/subcategories if properly organized/categorized.
Categories Like Travel >> Hotels & Motels Should be something like Travel >> Lodging >>Hotels & Motels (broke down by lodging type) and then broke down into regional or it is completely useless to visitors. The other option is to break it down by regional first like Travel >> Lodging >> Nebraska or Travel >> Lodging >> USA >> Nebraska or Travel >> USA >> Lodging >> Nebraska >> Hotels & Motels. There are way too many variables that are dependent on how many listings you have for each category on how to answer your taxonomy effectively.
Needless to say you have a long job ahead of you and if I started adding my 2-cents on how to structure your site, clients may see it and get upset with me…hehe
[edited by: The_Contractor at 12:58 am (utc) on Aug. 1, 2007]