I spend hours upon hours with chaps of mine from class playing both chess and Risk. Both are very fun and enjoyable games, and we can play them for days on end and still have a blast.
Monopoly, love it becuase I'm so good at it. I got a secret strategy that I will reveal now... just buy Mayfair and the other dark blue one and put a hotel on both, once the the people/person lands on one of them you get either £1500 or £2000. And also buy the electricity company and the waterworks. That is the best strategy.
Also chess and checkers are good. Scrabble is good aswell.
Hardly that secret its almost exactly what I do. Buy the electricity/waterworks, the train stations and the most expensive properties. It doesn't normally matter what anyone else does. You can loose almost all of your money moving round three sides in little dribs and drabs but on the home straight everyone else looses all of theirs.