As you've surely heard by now, Newsweek is celebrating the return of AMC's Mad Men on Sunday with a Mad Men-themed issue with a retro cover and loads of retro ads. Fast Company has posted 21 of the ads—some of which are original from the period, while others reimagine modern-day campaigns as they might have looked in the '60s. After the jump, check out four of our favorites. The Dean Winters "Mayhem" ad for Allstate is particularly great. Check out the rest at Co.Create.