Cirio on 26 July 2011
Although there are many flaws with the story and the anime itself was too lengthy, I think DBZ should be included in every list because it is one of the main reasons anime became relevant in the western nations (Pokemon too, but people don't think "anime" when they think Pokemon). DBZ opened the door to most animes we see today so I think it is one of the most influential IMO (and one of the most successful too).
