NEW YORK — Revelers at this year's Macy's Thanksgiving Day Parade gave thanks for the giant balloons that flew above the city streets Thursday after a blustery storm accompanied by high winds nearly grounded them for only the second time in the parade's 87-year history. "The balloons are the best part," 11-year-old Matthew Ragbe said as he watched them leave their launch pads on 77th Street and turn the corner to face the crowds of parade-goers, many of whom waited hours to secure a good viewing spot. Across the country, millions of Americans celebrated their blessings, gobbled up turkey and pumpkin pie and prepared to kick off the official start to the Christmas shopping season.