Grigori Iakovlevitch Perelman proved the longstanding PoincarÃ© conjecture and posted the solution on arXiv. One of the most difficult problems in Mathematics today. However, instead of publishing his work in a prestigious journal, he simply dropped it on an Internet archive. Maybe the Perelman story is meant to teach us something:
If your ideas are important enough and you get them out, people will pay attention to them, whether you publish in a high prestige peer-reviewed journal or not.
For more insights, see what Downes had to say.