Edited sentence: A secondary cause is the perfection of the voice acting; some of the lines are only funny because of the way they are delivered.The beauty of this show is that it straddles the fine line of the Adult Swim line-up.The plots, such as they are, are just excuses for the characters to be themselves; the show is funny only because of the interplay between the characters.While all the Adult Swim comedy shows are absurd to one degree or another, ATHF is just insane enough to make the more straight laced a little confused, without being quite so crazy as some other Adult Swim shows (such as Tom Goes to the Mayor, Harvey Birdman)