Darkseed: Metal. Just listening to it it's easy to spot. Also, all the links they have relate to metal zines and bands.
Paradise Lost: Also metal. They flirted with the Gothic genre a bit with their album called, surprisingly enough, Gothic.
Kidneythieves: Same. They're also not quite "underground" anymore considering they have a slot on the QUEEN OF THE DAMNED movie soundtrack. Personally, they sound pretty good (listening to their listening spot on the site) but then I like bands that rock with female vocalists. Easily availible through audiogalaxy I might add.
Oxygen Law: taken from their website from the "About O2L" section:
/div wrote:
VIIR: "O2L subscribes to old school Goth where the music is driven by dark atmosphere and melancholic contemplation. Oxygen Law is a Gothic band, and I have no qualms about that--about being 'labeled' and all of that nonsense. I have always identified with dark expressionism that draws upon melancholia for the development of atmosphere.
"O2L has become more and more classically oriented: etheric keyboard arrangements heavily layered with aggressive strings and drums. I prefer to work with one theme and then carry that constant throughout an entire work. Glass is a purely conceptual album--a stand-alone project. I doubt that I will ever do anything from this absolute, historical perspective again."
I think that says it all really.
As for the metal bands, don't ask me to classify what kind of metal it is as metal's not my genre. I can tell what falls under it's umbrella, but I wouldn't be good at putting it into the relevant subcategory (though speedmetal is easy to recognise).
Lilith