One of the bands that I heard about in the early 90s as being a bit of a cult favorite in the late 80s was Mysterious Art. They never got, as far as I know, any North American release, so they were already very tricky to find by the mid to late 90s when I was looking for them. But they had a huge hit in Germany in 1989.
I did a post on a song of theirs earlier, but in my effort to not be too predictable, of course, I missed their most famous song. They weren't exactly a one-hit wonder, but missing "Das Omen" is kinda missing the point, in many ways.