if you have patience and a lot of free time, watch One Piece. (But not dubbed, the dub is atrocious.) Anyone who gives it a shot through the opening arcs falls in love (it has an extraordinarily long setup that lasts like the first 70 episodes before getting into some of the real major storyline stuff aside from a few glimpses here and there). Suffice to say though there is a reason it is the best selling manga of all time. (Almost double #2 and #3, which is DBZ and Naruto respectively.)
It still scares me I've been watching a single ongoing series for almost 20 years.