I'm not sure how they'd count on a rationalism-o-meter, but I've enjoyed Kadrey's Sandman Slim novels tremendously.
Premise: a man is taken alive into Hell, and put to fighting in the arena. Every injury makes an invulnerable scar. He escapes to LA to get revenge on his fellow magicians who sent him to Hell and killed his girlfriend.
As might be predicted, he has a wiseass sense of humor.
Violence, confrontations, metaphysics, and snark-- if that's what you want, there are four medium-large novels worth of it. The first three are one story arc, and the fourth is a complete story.
This is the monthly thread for posting media of various types that you've found that you enjoy. I find that exposure to LW ideas makes me less likely to enjoy some entertainment media that is otherwise quite popular, and finding media recommended by LWers is a good way to mitigate this. Post what you're reading, listening to, watching, and your opinion of it. Post recommendations to blogs. Post whatever media you feel like discussing! To see previous recommendations, check out the older threads.
Rules: