At Tekko '08, I saw a group from the Godchild manga...I was really impressed! They had all of the main characters, in splendid detail, and I haven't seen that before or since.
Something that could be considered (sort of) obscure is Chiyo from Azumanga Daioh in her penguin costume. I saw one at Tekko '09, and was kind of in awe. It was so cute! I haven't seen that one anywhere else, either.