3. The Sims - 100 million
Taking the idea behind games such as Sim City and Sim Hospital to a micro level, The Sims series became a gaming phenomenon.
Since it was first released in 2000, The Sims has gone on to become the biggest selling PC game of all time. It is also was one of the first games to be as poplar with women as men, up to 50% of sales coming from women.