Well, I loved the Weetzie Bat books (collected into an omnibus called Dangerous Angels) a great deal. Her style perfectly fits the story she's trying to tell in this instance; so well that I continue to read her other books. I also very much enjoyed Ecstasia/Primavera. They were her first two books and thus not quite as solid, but she did some interesting things with Classical mythology in them.

I generally find her novellas to be hit and miss, and her short stories really mediocre, so I'd suggest giving one of the abovementioned books a try before writing her off completely. That said, I think she's coasting along on the name she's built for herself, as evidenced by the recent spate of novellas and short story collections.