Footman Frenzy

Though at first glance it appears to be shallow, BGH-ish, and impossible to lose, there's tons of complexity just below the surface.
Over two years old and still going strong, [i]Footmen Frenzy[/i] is one of the longest-running crazes on USEast and USWest, even gaining a feature spot in Blizzard's Spotlight Map program in 2005.