I understand why people don't, but for me, [Aliens/Mystical Forces/The PTB/Insert Genre-appropriate Cause Here] Made Them Do It is my all-time favourite fic trope, and that's what's at the heart of these stories. It's like somewhere in another universe, there's a series that's totally focussed on the crime/politics/supernatural integration aspects, and our books are the fanfic -- totally concerned with getting as much sex with as many different pairings as possible. Sure, there are some minor nods to a murder or power struggle here or there, but it's mostly to provide Anita with a reason to lose blood, control or a fight and therefore need to power up again by having sex with whoever doesn't run away fast enough. Fantastic!
The ardeur, a power source that she has to feed through sex, is a stroke of genius in shipping terms. Pick any characters you want to pair up, put them near her when the ardeur rises and away you go! A free pass for any shipper. Genius.
::ponders Anita Blake crossovers::
So, what's your guilty pleasure(s)? *g*