Udhay Shankar N [16/06/10 10:07 +0530]:
* Anita Blake (this one was a real pity - I loved it until book 9 or so, after which it became shoddily done porn. I object more to the shoddy part.)
Not really 'series' but there is a whole lot of Heinlein that falls into the same mode. Start off great and then go off into the weirdest combinations that sex and time travel can get you into. Quite spoils your memory of 'Starship Troopers', 'The moon is a harsh mistress', 'Stranger in a Strange Land' etc.