Most played computer game of all times

A reader asked me what in my opinion was the most played computer game of all times, measured in man-hours. He suggested that unless you treat the expansions as different games, World of Warcraft would hold that title. But I'm not so sure that this is true, because there is a strong contender: Solitaire. Due to having been included with many versions of Windows, even on office computers, countless people wasted their office time playing Solitaire. Problem is that this game doesn't show up on sit

World of Warkraft...