“That” Time Magazine Cover

For anyone who hasn't seen or heard about it, this week's Time magazine cover depicts a young mother breastfeeding her three year old son.  One story, including copy of the cover, is here.  The lead article is about attachment parenting which is not a new phenomenon but which certainly raises strong opinions amongst parents and others.  The cover of the magazine itself was clearly meant to provoke discussion – and has provoked a lot so far.  It got me to wondering which other magazine covers have made the most impact (and sold the most magazines) over the years.  The year that Time magazine nominated "You" as "Person of the Year" springs to mind.  Any others?