Still not quite aligned but getting closer... On AA flights you get to choose any food item, on US flights you get the a la carte snacks. That translates to Pringles, M&Ms etc.
"Enjoy a complimentary snack and standard alcoholic beverage in the Main Cabin on US Airways, American Airlines and American Eagle flights. Choose any food item on American's menu or any snack from the US Airways a la carte menu. Standard alcoholic beverage includes one liquor miniature, beer or 187ml bottle of wine (items may vary)."