Can't think of too many Halloween episodes. I already posted one with Blue Exorcist. One episode I found funny was an episode of Hayate the Combat Butler. Ayumu is always shown in walang tiyak na layunin scenes with food. In one such walang tiyak na layunin scene, she went trick or treating hoping to get some candy, but then lamented that she wished Halloween would catch on in Hapon as everyone just thought she was nuts. Couldn't find a picture, but here's one of her all upset. I haven't watched enough Shaman King, but I wouldn't be surprised if that had a good Halloween episode.