To a fashion novice, determining the best Met Gala red carpet looks of all time sounds like an impossible task. There are nearly six decades of events; hundreds of celebrities; and dozens of hard-to-interpret dress codes to sift through. With guests hoping to out-flex one another with rare archival fashion and towering headpieces—not to mention the outfit changes they pull off in real-time on the carpet—how does anyone choose? Here's the thing: my fellow Marie Claire fashion editors and I have been covering the Met Gala red carpet for years, tracking down designer credits and interviewing the stars for insight behind their custom gowns. In other words, we know the annual Costume Institute benefit inside and out. When I asked the team to share their Hall of Fame-worthy picks from all of Met Gala history ahead of the 2026 installment, they didn't hesitate.…