I decided to split Industrial music into subcategories. Although I'm a fan of all the different styles that carry the "industrial" tag, I thought it would be useful to at least split things between old-school Industrial (experimental, noise, whatever) and Industrial Dance (electronic beats). In addition, I made up a category called Industrial Rock, which includes a lot of "industrial with guitars", "industrial metal", and various kinds of "alternative rock" that has some industrial elements but is still different enough (in my opinion) from either of the other two industrial categories.
The split between Gothic and Atmospheric may make absolutely no sense to most people, and I suspect that many of my Atmospheric entries can be found on almost everyone else's Gothic list. Well, after all, this is my site, so I can define things any way I want, and I prefer to make a distinction between the two. Atmospheric is my term for music of the more ethereal variety, the kind of stuff you'd typically find on 4AD or Projekt. This is a really broad category, and includes quite a bit of "alternative" rock that tends to be on the prettier side. The artists on my Gothic list, however, are darker and more typical of the fare you'd hear at a goth dance club. This includes all the old-style UK goth bands as well as a lot of newer "darkwave" featured on German labels like Dion Fortune and Glasnost.
Admittedly, the remaining categories (Japanoise, Metal/Death/Grind, Ambient, and Techno), are very incomplete simply because they're really not in my area of expertise, and there are plenty of other sites that cover them in more detail. They're here because I do have some interest in those styles of music, and perhaps other people can help flesh them out over time.
I'm very interested in other suggestions for new categories or ways to do the existing ones differently. Feel free to give me your ideas.
As I mentioned above, you don't have to use the categories at all if you don't want to, because everything is indexed alphabetically as well.