Which episode has had the most British subjects? By "most British subjects", I mean either the episode with the highest proportion of British posters ("most" in number) or the one in which the British posters were most overtly British ("most" in degree); take your pick.
I think that the trash rubbish fetish wins in both categories, but I'd pick tickling as a runner-up for the first and hoop earrings for the second. GirlPits is probably up there too.