OMG, stupid me, not realizing I WAS talking to the OP. Sorry about that, didn't mean to bash you. The thread is very interesting and it's good you started it, the thing is I understood a slightly different meaning from your title than you seem to have meant.
In the usual Internet / TV talk "adult" is synonimous to porn, such as "adult entertainment", so when you said "your favorite adult themed book / author" I immediately thought about hard porn books and not about for example an SF book containing sex like Miles Vorkosigan, while you obviously meant the other thing rather then the first (I don't know if you even know of the first)...
Anyway let the discussion about everything from innocent romance to kinky sex in literature continue on...
