"Misunderestimated" = a George W. Bush-ism (like "nucular," except he shares that one with nine-year-olds everywhere), so it's really sad if we actually see that popping up in usage.
"Hella" isn't just a contraction, right? It doesn't really mean "helluva" but is more like "very" or " super" or "really", is that correct? (Spearhead, 1995: "The way to my heart/is through a garlic clove/it smells hella sexy/when it's cookin on the stove.") Kind of like "wicked" amongst the Boston locals: an adverbial intensifier ("the brawl in the Sox/Yankees game was wicked cool!")
After moving back to my hometown recently, I was reminded of southern Indiana's version of the South's "y'all:" a contraction of "you ones" (or something) that comes out "you'uns." As in "You'uns have a good time at the Speedway this weekend." Pair it with another local favorite, the construction "had went" instead of the correct "had gone," and throw in some awkward prepositions, and you're in Hoosier Heaven!
"If you'uns had went to the quarries to swim at instead of the lake, we would've known where you was at!"