It sounds like you run the sort of game I'd like to play in, toothill. Wait a minute - I am playing in one of your games! :?

No, I mean it'd be great to play with you at the same table. The tyranny of distance ...
I tend to run pretty dark games, too; livened up with the same sorts of humour you favour. Between trusted companions (ie other players, close NPCs) there are a fair number of good natured insults traded, along the lines of Slaine and Ukko's relationship.
However, I really play up the deadly earnest of a true insult directed at a stranger, rival or foe. "In Slaine's time insults were valued like swords" and wounded honour stings as much as wounded flesh. The PC's really get into crafting great Slaine-worthy taunts and I reward them with bonuses for particularly appropriate ones. The straight Charisma plus BAB taunt check is a little too random for my liking, so the bonuses help out there.
The players really love unsettling a foe with words to gain a tactical advantage in combat or using them to gain the upper hand outside of it. However they're all aware how deadly a contest of taunts can become and
hate when they end up maddened themselves. :twisted:
A bit of humour really is important, though. I like to populate the game with all sorts of oddball characters: outcasts, witches, druids, dwarves and the like. People removed from the tribal system to a degree, like Ukko, who can interact with a slightly different, almost more modern sensibility. They can help to highlight the darkly humorous absurdities of the age.
Sometimes campaigns are small, village-based affairs, dealing with cattle raids, local magical sites etc, other times focused on wanderers finding their way in the Land of the Young. As far as atmposphere goes, my favourite Slaine vibe is the gritty, "lower powered" early black and white days of Kincaid, Bellardinelli and McMahon where the focus tended to be on more "mortal" concerns.
There's still plenty of emphasis on the magical nature of the land and the closeness of the Goddess in my game but I haven't branched into the higher powered concepts with my players yet. No sign of the Cythrons and no "warrior through time" stuff for the moment. :wink: