La Piazza Al Forno (Glendale, AZ), Slim's Last Chance Chili Shack (Seattle, WA), Twisted Root Burger Co (Dallas, TX) Guy Fieri checks out some places doing America's favorites: Burgers done every which way at a joint run by culinary school grads i... (more)n Dallas; An Arizona pizza joint serving up family recipes; Plus a Seattle chili shack.