10. Monopoly
No countdown would be complete without Monopoly. There are countless versions of the game. There is even a millionaires version of the game that comes with REAL CASH as play money. There have been more monopoly board games sold than any other board game. There are plenty of comedians that joke how Monopoly will take 6 hours to play, but if you understand the rules you will find tactics you can use to beat your opponent quickly.
In fact, there are even world competitions where people come from all over to compete for the title. My favorite version of Monopoly is the one that has an electronic bank, so if you have someone trying to sneak $100 from the bank, or slow with math, this new feature will also speed up the game immensely.