These days, it's pretty much anything by Laurell K. Hamilton (i.e. Anita Blake & Merry Gentry series).
When I first started reading the Anita Blake series, about ten years ago, I really liked them. But by the time I got past about the eighth book in the series, I was less impressed. They just seemed to have gotten really weird and overwrought. But I chalked that up to a series that had run too long, and I was really excited when LKH brought out a second series, the Merry Gentry novels.
I enjoyed the storyline in the first 2-3 of the Merry books, but I started to be annoyed at the poor writing and almost complete lack of editing. The same half-dozen stock descriptions of characters, used over and over and over and over.... I swear she's got macros for these programmed into her computer! It's really annoying.
But the worst part is the porn. In both series, the later books devolve into mindless, gratuitous sex scenes, in which the author seems to be trying to one-up herself on the kinkiness scale. I like a good, trashy romance as much as the next person. Generally, the trashier the better. :p But these are just...pointless. They're like bad fanfic; all porn, no plot.
I really miss the story development that she had in the early books. She had some really neat ideas for her universe, characters, etc. But they just got too weird, and once I started to notice the bad writing & editing, I just couldn't stand to read them anymore.