Since there are so many language resources on the internet nowadays, I was wondering if there is an online dictionary(or any other language tool) that would list the words not only in the alphabetical order, but also by the frequencies of their occurrence. I don't care how the frequencies are calculated - it may be based on something as primitive as google search results count or it can be based on occurrence in newspapers/books only.
The reason I am looking for such a tool is that I have been searching for an efficient means to enrich my vocabulary for a while. The best I found so far is vocabulary.com. The problem with vocabulary.com, however, is that it more often than not suggests really strange (not to say weird) words that a lot of native speakers don't even know. I have nothing against learning literary words, but I think I should get to it only after I've covered most of the mainstream words. That's why I am looking for a tool which would arrange words according to their occurrence. I would then pick the next N words each day from that list, feed it to vocabulary.com and learn them using their technique.
So, is my request too absurd or is there hope I could find what I'm looking for or at least something similar?