i just stumbled upon this artist by accident and browsing through his works i was blown away.
his work shows a unique stile which could come from the eighties-or from some experimental person from the far east, but no…they`re made actually almost a hundred years ago. while i thought that the modern fantasy (or sci-fi) style was coming from the fifties this discovery made me change my perception on this matter.
http://commons.wikimedia.org/wiki/John_Bauer
http://runeberg.org/jbauer/
it would be nice if this thread could be a collection of links about similar significant artists who inspired the following generations. if you know someone like this feel free to post links.
sure, the most known ones can come as well 
I am not really sure about the association of terms “artist” and “ahead of their time”; I’m still cogitating over this. Anyway, one artist that stands out to me is Winsor McCay. He was known as a top-notch draftsman but it wasn’t until I saw a DVD that included movies of him sketching in real time that I truly appreciated how good he was. He did some early animations by drawing each cel individually — well, not a cel at all but individual sheets of paper.
If you like to sketch at all, here is a fascinating video made in 1911, before audio and color. I have heard that the story — that he was challenged to make a moving animated short with 4000 handmade ink drawings in one month is true. I don’t know if he actually met the delivery date but … he is really fast.
Lyonel Feininger
http://images.google.com/images?hl=en&rlz=&q=lyonel+Feininger&um=1&ie=UTF-8
They say that the Kin-der-kids was his best strip, but the art in Wee Willy Winkie’s World is far superior. He was a cubist painter and was one of the guys who started the Art Deco movement, but his stuff was far beyond just some simple aesthetic. This, to me, is what good abstract art is all about. It’s iconic and symbolic, not just an exercise in composition as 99% of abstract art is. Some of his comics work could pass for a modern-day attempt at riffing on Mignola, but 100 years too early to be a copy.
Salvador Dali has made some of the most awesome pieces ever, I think he diservs one placeon this list http://images.google.com/images?hl=en&client=safari&rls=en&pwst=1&resnum=0&q=Salvador+Dali&um=1&ie=UTF-8
And if we’re not only talking about visual arts I would say that the composer Jean Sibelius and the author Douglas Adams.
Winsor McKay <-- second’d.
Nicola Tesla. For reasons we don’t understand yet.
J.S. Bach nearly (re)invented music. He ruled. He was forgotten and rediscovered and he ruled again.
Da Vinci nearly freaking built a helicopter. Beware of his art skillz too.
Jules Verne foresaw submarines and trips to the moon (though I don’t think so highly of his proposed method).
Isaac Asimov. He foresaw debugging programs, computer animation, the three laws … and that’s just off the top of mah head.
How can artists be ahead of there time?I see Isaac Asimov, Da Vinci, and those guys, but i mean like painting and stuff. I don’t get it.
Artists often produce work that is markedly different from what is commonplace or fashionable at the time. Later that style or innovation becomes commonplace or fashionable…
The secessionists for example produced art and architecture that most would call “art deco” 50 years before art deco was a style…
Also, the world around us affects us, this leads to zeitgeist, where many people independantly have similar ideas and produce similar work, just because of the state of the world and culture around them… Artists are ahead of there time if their work anticipates a coming zeitgeist…