Conde Nast Art
I'm so excited to share this because like many of you, I love magazine covers from times past. Conde Nast has a beautiful online art store called Conde Nast Art where you can select your favorite print to decorate your walls or order them as greeting cards. They're currently offering free shipping, too. Their prints are taken from the covers of Gourmet, House + Garden, Mademoiselle, Vanity Fair and Vogue and you can search by category (city life, country life, art + design, etc), by decades (1910-1950) or by artists (from Alajalov to Zeilinger).
If you're on a budget but love Vogue prints, there's a book that my mother had when I was growing up, the Vogue Poster Book, and you can still find it for under $50 online if you look hard enough. It contains full size 11 x 15" color pages of Vogue covers. Some stores try to sell it for $100-$300 but don't fall for it, just this past weekend, I picked up a copy on eBay for only $30 shipped. Search for ISBN 0517520079.
(images from conde nast art)