Yesterday my wife and and I went downtown to visit a certain store, only to find that a lack of staff made it closed! Since we had already put some quarters in the parking meter, we decided to visit some other stores we had not ever been inside.
At one of them we bought a new board game, Carcassonne. We also got an expansion set. (Prices were much less expensive that at these links!)
We've now played the game four times, twice with friends and twice just the two of us. It's very fun and certainly recommendable.
We have not tried the expansion yet. It will change the game a lot.
The basic game is a "building" game where you are putting together a map and claiming which "features" on the map you are investing in making big. There is very little direct competition among players, since placed map pieces cannot be removed (or moved) and bids cannot be withdrawn. Also, it takes notable luck and skill to have a bidding war over a particular map "feature".
The expansion allows a player (again with some luck and skill) to remove their own or opponent's bids. Thus you can perhaps withdraw your bid on a "feature" that turned out to have low potential, or remove an opponent's bid on a high-potential "feature". Until we have tried it, we're not sure if this will make the game more fun or ruin it.
UPDATE: We've now tested the expansion in a four-player game, and it was helpful. The main effect relates to how the game starts with a the map divided into two halves by a road, and the first players to start farming on either half typically have an advantage. The expansion removes the likelihood that early farming will be worthwhile, thus making the game more fair to the players who do not move first or second.
UPDATE: The rules (or perhaps their translation into English) have a couple vague points. While searching for clarification online, I found out the game has a blog!