I think this is probably a commentary both on the game and my wife but she and I recently ran through at least five rounds of Arkham Horror. I feel pretty lucky to be married to someone who will engage in such geekery but for now let's see how the game measured up after so many plays.
Arkham Horror was reviewed earlier but briefly it's a cooperative game in which players move around a board fighting monsters and having supernatural adventures. I'm happy to say that some elements of the game really shine after multiple playings.
Firstly, this is truly a cooperative game. Not simply because the players win or lose as a group, but also because the players need to help each other to succeed. We had our best success when we would plan out how our characters in the game would support each other: "OK, I'll fight that zombie so you can run past it and get to the church and remove my curse." Now some players may be put off by this need for coordination but I think teens could get a real charge from "teaming up" with their parents to defeat a menace. I know for me it made any victory all the more satisfying since it was sared.
Arkham Horror also delivers in variety of play. The characters have "encounters" in the town. They may meet a wandering creature, find a hidden scroll, or be whisked off to another dimension. There are enough options and possible events to give the game huge replay value. You also have a number of strategies to try and after many games we haven't found a single approach that's foolproof. The end result is a lot of replay value.
Finally, Arkham Horror is a sort introduction to role playing games. You have a "character," they acquire items, skills, and spells, and then they have an adventure. This is a nice choice for those people who have a secret goal of introducing everyone in their family to role playing.
Arkham Horror does have clear caveats. I think it's best for teens and up, it is an intimidating game to first examine and the rules could use some editing. You will not just dump this on a table and play "out of the box." With a slight amount of work, however, this is a very satisfying game.