Hi you may wan't to have a look at pogo.co.uk they have lots of great games & community, it's part of the EA Games network, if you join add me as a friend (HisDibbs) i'll give you a full pass for 5 days. I know King.com has Yahtzee & others. Or why not try http://www.cluedo.com/how-to-play you will have to register but it looks like they have different challenges for just cludo. I hope this helps, David.
I'm a member of a site called Gumshoe Online. You play a detective and you find clues, speak to suspects, play mini-games (sometimes quite challenging!) and then present your evidence to make an arrest.
You'start with a few locations and as your evidence grows, more open up.
It IS paid for, but there is a free starter 'case' and it's not that expensive - and it can keep you busy for days at least!
Have a look and see what you think.