Just a transplant from California, trying to figure out what everyone around me is trying to say.
  1. "I'm fixin' to [insert verb]."
    Alternate: "I'm fittin' to ..." Translation: I'm about to [...].
  2. "Do what?"
    Translation: "please repeat what you just said."
  3. "WHAAATTerburger"
    Translation: Whataburger. Gross fast food chain that Texans think is good because they don't know what it's like to have In-n-Out.
  4. "Bless your heart!"
    Translation: "You've just done or said something stupid and I'm going to try not to be a dick about it."
  5. "The confederate flag is just a symbol of southern heritage!"
    Translation: "I am incredibly racist."
  6. "It's hotter than fish grease!"
    Translation: pending clarification.
  7. Them there: a collection of people or objects over yonder.
    Suggested by @Gin
  8. Over yonder: somewhere between 6 feet and 10,000 miles away from the person speaking.
    Suggested by @Gin
  9. "Thataway"
    See: Over yonder.
  10. "Big Red is my favorite soda."
    Translation: "I have terrible taste in soft drinks."