There are some that are quite beautiful. Say what you will about the plot and whatnot - but the Deathnote anime was animated VERY well.
I think the difference has to do with the budget and how long the series is. The dragon ball series, pokemon etc were several several SEVERAL hundred episodes (and are also much older series) and it would cost a lot more money to get them animated up to snuff. Things like Shiki and Another, by comparison, are much shorter - no longer than 26 episodes, and are animated much more elegantly.
Although, that may also be an issue with regards to their relative ages....