"Really Most Surprising"

From an article by Adam Gopnik in the New Yorker on Damon Runyon:

So Runyon's key insight into American slang is double: first, that street speech tends to be more, not less, complicated than "standard" speech; but, second, that slang speakers, when they're cornered to write, write not just fancy, but stiff.

I believe I have seen that in cover letters I have proofread for patrons.