That should have stayed a manga only!

I don't really see why people are saying Naurto should of stayed a manga. Yeah, the fillers are bad, we get it. But when you see the actual show, it's a very faithful adaptation and has some real good animation. There are weak points, yes, but it's still a good anime if you take out the filler(which no one is forcing you to watch, anyways).

As for real anime that should have stayed as mangas, there are hardly any. The ones mentioned already, with the exception of FMA I agree with. FMA, while going on and doing its own thing is still a good show, you just gotta look at the anime and manga as different entitie's in the same world.

I think Hokuto no Ken (Fist of the North Star) should have stayed as manga, though. The anime is alright in it's own right, and the voice acting is awesome, but the ammount of stuff they had to censor, the filler, the stretching of the first 2 volumes into 26 episodes, etc.. is just too much.

Jam it back in, in the dark.