It's probably tempting fate (and player hijacking) to assign a falvour to a campaign that started last Monday, but my tastes are well established, so...
Lovecraft is a big influence, not so much in issues of detail (e.g. no mythos deities or monsters) or the eldritch superabundance of squamous adejectives, but in the sense that there is big, nasty stuff out there that you can barely hope to understand, let alone defeat . You might guess that this isn't an epic level campaign, and that in the past I've played/DM'd rather more Call of Cthulhu than D&D.
The inspiration for the current campaign - though the concept has strayed a very, VERY long way in the interim* - was the
Viriconium stories by M John Harrison. Though I have toned down the ennui a little, otherwise....
DM: Roll the dice
Player: 20!
DM: You fail.
Player: But that's a total score of 32!
DM: It doesn't matter. It's all futile anyway. Why not eat the table cloth instead?
* - in other words, Richard, that means that reading the stories won't give you any big clues!