Planet Express Onesies
After Fry accidentally ruins the American Revolution in "All the President's Heads" (s06e23), the Planet Express crew return to 3011 only to find that America's remained under British control the whole time. There's a 1.5 second of the British version of the Planet Express logo and, well, here it is. Can't get much more obscure than that.
Tags: flag, time travel, history, logo, british