I have only watched a couple partial episodes of anime with english dubs, and I feel if that is the form you are watching, you certainly will find it childish. The dubbers in the us just make it very cartoon-like. Try watching some with subs if you haven't already. I am also very picky about the animes I watch. Try looking them up and reading a synopsis first to see if the story will go in a direction you may actually be interested in. I could give you some suggestions of shounen that are semi-deep, but all of our tastes are SO very different, it's almost hilarious to me.
