what I mean to say is in all shows you WILL find a bit of immaturity... otherwise it would be a show about nothing, which is pretty much what Metropolis is (though it does balance a LITTLE, but it is the MOST mature with the least amount of immaturity and fanservice out of that lot).
As I said one cannot be mature without learning to enjoy (nay, tolerate) the immature. Thus the MOST mature anime WILL have immature elements. Pokemon is more than just raising animals to fight, it's also basic morales like respect and care. Like you say, a little weak, since it's so basic, so the ten year old aspect is strong. But 20 year olds that occasionally watch something 'immature' as that shouldn't be ridiculed, cuz it can be used as a reminder

and some ppl just like living their passed in their free time. (edit: bad excuse as it may be... I'm tired what more can you expect! lol anyway watch an immature show- not just EPISODE, the entire show- from beggining to end and I'm sure you'll find there's more to everything than meets the eye)
Anyway what does this have to do with you? All I'm saying is you can't demand mature animes without toleration for immature. You won't find mature anime without immature overtones mixed in... rather if you did I doubt you'd like it. (ie Angel's Egg) Perfect Blue or Hellsing are probly decent examples of mature animes with very little of immature, sure BUT that is substituted with fanservicy gore and sexy

. Those things are pretty damned immature (ie Celes is one giant boob as is most anime heroines lol, Alucard is the tall, dark, handsome badass stereotype as is most heros- including those in hollywood movies). Most anime is immature, that's why it's anime.
oh nevermind I'm just babbeling :/ lol mostly just because you said you can't stand immature and looking for mature, like Hellsing

. Trust me I could find fault in anything :/ my bad is that you may know all this but simply don't want an immature extravaganza like Tenchi Muyo, you KNOW all this geeze!! lol whatever :/
If you do not think so... you will DIE