I can't speak from Memorial Day Weekend experience, but I'm guessing Epcot would be the best bet. So far this year, we have gone to WDW for MLK Weekend, the second half of Presidents' Week, and the first weekend of Spring Break crowds. Each time, Epcot was the least crowded. MK will definitely be the most crowded, and AK and MGM are so much smaller, that they always feel crowded after the first 2 hours. HTH