If I have one complaint about Ugly Americans, it's that the demon folk are just a tad too dominant; every story involving some demon trial or ritual is guaranteed to be the A plot of that week's episode. Not that they don't make for good stories, but I wish the writers would pay the same sort of attention to some of the other species more than once in a blue moon.
The robot in Mark's group got the best line of the show, IMO: when the J9 unit spits out a punch card and hands it to Mark, everyone turns to the robot to translate. He grits his teeth and says, "I love how everyone assumes I can read punch card." As the only non-white student in my 12th grade philosophy class whom everyone automatically turned to for "the black perspective", I completely related to that.