True, many animes are enjoyable. I watched a lot of anime during a period of being charmed by this phenomenon, hundreds. For all their charm, one wouldn't fail to notice that often stories lack focus and good writing, etc.Generally I'd agree that most animes are indeed either aimed at teenagers or feature them, but I'd also say that a lot of them can be enjoyed by adults as well.
Another matter is you can't recommend many anime masterpieces to the general public. I doubt an average person with no special interest would sit through Neon Genesis Evangelion just to see a couple of last episodes. And if he or she would, they could find those episodes absurd or boring, as they mostly appeal to those interested in how their psyche works and mostly on a simple level addressed to teen audience.
I agree with your picks, though, and can add some others, like Nana or the Miyazaki movies. However, Death Note I named because it's quite unique even in terms of movie industry, or at least I've never come across something alike, and it isn't "Japanese" enough to put people off. Monster is more or a mixed bag, the pacing might be mellow for some, but it stands out.