Ranma ½, Beelzebub Recommendations
Both have the main character being the strongest, encountering rivals along the way who constantly re-challenge him time and time again. Many times involving a new technique or way of powering up for the rival side character to stand up to the MC this time around.
Both have filler, many episodes of which is dedicated to a certain side character. Developing the character further.
Both are action shows where the MC blows away some side characters (Beelzebub, the MK5. Ranma, Kuno.) Sending them flying into the distance. It doesnt sound like much, but it happens so often it sort of sets a tone for the show.