Twilight Struggle
"Twilight Struggle" was the highest-ranked game on BoardGameGeek from December 2010 to January 2016. As of August 2018, the board game occupies a fifth spot. Being released in 2005 it is the oldest board game in the overall top 10 ranking.
Real-time strategy
In the United Kingdom, the earliest real-time strategy games are "Stonkers" by John Gibson, published in 1983 by Imagine Software for the ZX Spectrum, and "Nether Earth" for ZX Spectrum in 1987. In North America, the oldest game retrospectively classified as real-time strategy by several sources is "The Ancient Art of War" (1984), designed by Evryware's Dave and Barry Murry, followed by "The Ancient Art of War at Sea" in 1987.