If anyone revealed a truly great keyword, it would cease to be one within 24 hours. That's why people keep them a secret when they find them. For the most part, the "super keywords" are a thing of the past and values have sort of leveled out as competition became fierce.
I wonder how much money the first person to realize "mesothelioma" was a blockbuster keyword made. That's one of those very small niches that happens to have a lot of money in it (thanks to multi-million dollar class action lawsuits). Law firms at one time were paying over $100 per click for these terms, because a new client could mean hundreds of thousands of dollars in extra revenue for them. Then in a matter of months there were a million different websites about mesothelioma, and it became nearly impossible to get anywhere near the top of the SERPs. As the leads became poorer, the law firms offered less money per click, until "mesothelioma" became a downright terrible keyword to target because of high competition and dwindling value per click. Mesothelioma is still a small niche in the real-world, but it's got a huge presence online as everyone got greedy and starting going after the big advertising bucks.