Yup! your right about that.... wish I could watch anime from 1980s onwards..... I feel Mainstream Anime stories and plots are limited. The Older ones are much more richer in stories.
If you think about ao exorcist, kaminomi, and many others, you have a point, these are never to exciting...
I wont get in detail about the 80's, i know a few titles but its was long ago...
In the 90's many masterpieces that redefined the industry where made, the golden age of the anime...
But speaking of the 80's there are a few titles that capture those times very well, when many of the "world masterpiece theater" anime where made, but in the XXI century, even these days there are still titles of the famous "world masterpiece theater" being made, like "anne of green gables" or "Les Miserables: Shoujo Cosette", these are modern masterpieces of other times...
I could give you another example, Saiunkoku monogatari, it is a beautiful story loosely based on ancient china, less about wars but more of a romantic story with heavy political and economical influences...
Kemono Souja erin, i have said it many times, this is a fairy tail like those you only read on child books, but dont let the childish book cover fool you, this is a very serious story, while any children of a certain age could enjoy it, only a grown up adult can fully understand this complex world...
Another perfect example: Emma: A Victorian Romance, this is another great story, watching it, is like reading a romance...
Those are some examples of the best that was made in the early 00's because in more recent times, there are great examples of the best that has been made...
In no specific order: Letter bee, it is an unique fantasy tales on a unique and unreproducible world, the beautiful animation, strong character and a good story to make it move forward, makes it a masterpiece...
Madoka, this years strongest "hit", this is an anime that broke every convention, any rules, guidelines that might have existed where broken and a genre was redefined, fans raged and cried in almost every episode, legions followed it and it is the best selling anime in history, and for a reason, fantastic animation, strong and interesting characters, fantastic music and an unpredictable story...
Wandering son, beautiful animation and character design, an unique story, a bold move, but the way it deals with life specially for some maladjusted ppl on society, it shows us how they deal with it their way...
Level E, a healthy mix of comedy and sci-fi, based on old but successful manga, it shows that you dont need an harem or a female only cast to do comedy, and not much anime can fool you twice in a row, the anime will fool even itself in the end...
Shiki, simply the best horror anime after the classic higurashi naku koru ni and the best about vampires...
Just some examples
The solution to your problem is not watching mainstream anime, every season there are a few titles that escape the mainstream stream of anime, and even once in a while a titles is made that redefines a genre or invents a new one...
You probably just dont watch enough anime or dont know where to look...
I have a tip for you, check my posts from page 300 onward, i have made some quality recomendations, and made an extensive exposition of what anime is airing nowadays and whats worth picking up...