I recommend just about everything written by Jesse Venbrux (clickie)
. It's free.
In reverse order of suitability:
* Karoshi series (though the application of "consistent rules" is debatable :)
A quick note about Karoshi: the theme of the game is largely about trying to get the main character to cutely and creatively kill himself. Given that you enjoyed Blackthorne I don't think this will be a problem, but just so you know...