Naruto, Bleach, and One Piece.
So named because they are the three most popular shonen manga currently and the most popular universes used in the OBD. It is estimated that over 60% of all OBD matches contain at least one character from the HST. Many people have complained that these series are overused, and the OBD needs fresh characters and verses. However it seems that the HST will always be a mainstay of the OBD. One reason for this: when these series are not used, the resulting threads are usually just not very popular.
Recently the HST has powered up a lot. They have many characters ranging from town+/city level+ up to country+/continent levels with the Naruto top tiers reaching at least small planet level+. Their speeds can range from hypersonic+/massively hypersonic+ up to sub-relativistic+. (depending on the character)