Wow, so much hate for One Piece in this thread. Do me a favor, don't ever watch One Piece please. Even when Naruto and Bleach end and there are no more good animes on while One Piece is only half way done, don't ever look it up. Seriously. You will just judge the series and put it down the entire time watching it. Save yourself the time. Leave the epicness of One Piece to real fans. We don't need half ass fans.
OT: For me Bobobo-bo Bo-bobo was really bad. The dumb randomness was horrible. Shin chan is up there too. Salor Moon is probably just as bad, not for the same reason though. When I was a kid, I'd come home and watch Salor Moon and DBZ on Toonami and thought it was the greatest thing next to sliced bread. When you go back and re watch it when you are older, you ask yourself, I thought this was entertainment? I did that with DBZ recently and was like wow, there is like no plot or character development. Salor Moon was even worse, same generic episode over and over and over and over... They are having fun, bad guy appears, Salor Scouts try to beat the enemy, can't do it well, Salor Moon comes, uses her awesome powers and wins. It was amazing as a kid, but when you get older and watch it you are like, wtf and I watching. That's why I think there's such a love hate relationship with DBZ. Younger kids are like, OMG THE BEST THING EVAR!!!! and the older generation are like yeah it was good as a kid but now it isn't as good as other animes, like *insert badass anime here*
Oh and to answer the question above, Dragon Ball is made up of 3 different series. Dragon ball, when Goku was a kid and growing up, DBZ the one we all know so well, and DBGT which is an anime only non cannon story that takes place after DBZ. Goku finishes training Uub and gets wished to be a kid by the horrible plot device black star dragonballs... Oh and Goku goes on his epic adventures finding the balls with his granddaughter pan to find then to make him old again, And we get introduced to SSJ4 Goku.
I wouldn't say the above are horrible, its just some animes are meant to appeal to certain age groups. When you watch them outside that age group, they just aren't as good as animes that are in your age group. The reverse can be said too. When an anime is too mature for certain young kids, they don't get everything that goes on, specially when things are so in depth and fly over younger people, or when the joke is meant to appeal to the older age groups on purpose. Anayways, enough ranting, its all just opinions anyways.