AsoBrain

If you like board games then you'll love AsoBrain. They have Carcassonne (called Toulouse) and Settlers/Seafarers of Catan (called Xplorers).
You do have to register to play, but it's free. You can play against friends, or if no one else is online, against the computer. Hello Carcassonne, good bye spare time!

Some of the rules are different than in the version of the board games that we have. In particular the points for farmers are 3 points per city (instead of 4 points).