One of the most unique co-operative games that I've played recently is Hanabi. (Sorry, no Amazon link. Also, my copy is actually of "Hanabi & Ikebana", but I'm yet to actually try Ikebana. There are two sets available that I know of, the set that I own, and a set that only includes Hanabi and is in a nice tin box.)
In Hanabi, the players are working together to try to create the most amazing fireworks display that the world has ever seen. To do this, obviously, the fireworks have to be shot off in order - this builds up to a nice crescendo. Each player has a number of cards in their hand. These cards face all of the other players, and the person holding them cannot see them. On each turn, you have the option of doing one of three things: playing a card in your hand (each color must be played in order from 1-5; if the play is invalid, then you use one of your three strikes and lose your card), discard a card to gain a clue, or use a clue to tell one of the other players all of the information possible about either a number or color in your hand (such as "these *pointing to cards* are all of your red cards"). Once all three strikes are used, then the game is over, and the players count how many cards they successfully played. Conversely, if the draw deck is exhausted, then each player gets one more turn, and then the game is over. Scores run from 0-25, or 0-30, depending on if you are using the special "multicolored" fireworks (these are in my set, but not in the tin set, I believe). If you get a perfect score - well, then you're much better at this game than I am, and you are free to leave a comment to gloat about your awesome Hanabi skills.
Whenever I talk to people about co-operative games, the response I inevitably get is, "yeah, but I could also just play that game by myself." Either that, or they have played with that one jerk that is constantly telling everyone else what to do. (Every group has one of these; it has been implied that I have even filled the role a few times.) However, Hanabi addresses both of these issues. Are you being bossy and telling everyone what to do? Then you're probably cheating - because to tell someone what they should say (or play), you have to at least indicate something about someone else's card. Plus, you have no idea what is in your hand! You may have a hand full of critical cards, and if you'd just stop ordering people around for a minute, they'd tell you about what you have! Also, you obviously can't play it by yourself. That would just consist of not looking at any cards and blindly hoping you could play them in order. That's not really much more fun than just counting how long you can keep your eyes shut without falling asleep.
|Get used to staring at this.|
Now, though I think that Hanabi is a fabulous game (though I only listed two pros), there are a couple of cons. First off, I feel like I'm always cheating in this game. If you want to play by the strict rules of the game, then you really shouldn't be saying anything about what people might have except for what the clue allows. You shouldn't be discussing with another player what to tell a third person, as you might let something slip. You also have to be careful not to do things like "this card is a "3"... and so are these two." (Which would be obviously telling them which one was the "3" that they were looking for.) With this said - games are about having fun, so if you're willing to be a bit loose with some of these rules, then go for it. It may make the game a bit too easy for you, though.
|Putting on an amazing fireworks display!|
A third con, that I feel is somewhat minor, is that often during the game each player will settle into a role of clue giver, discarder, or player. What I mean by this is that often the same people will be performing the same action repeatedly. If I am never told anything about my hand, then I probably won't be playing anything. I'll probably be giving clues. Or, if I'm told nothing about my hand for long enough, then I may be just blindly discarding cards and assuming they're junk. This can get somewhat boring and even a bit frustrating. It's not an "oh my goodness, I hate this game" kind of frustration, but sometimes there will at least be a hint of "I sure wish I could play something."
Overall, I give Hanabi an 8.5/10. It is an incredibly different take on the co-operative and social interaction genres that I think meshes together beautifully. However, as I've played it more, I've realized how much the order that cards are drawn can affect the outcome of the game, and so it has knocked it slightly down from a more elite score. It's still worth checking out, and I'd encourage all of the co-operative game naysayers to try it out!
If you are looking for interesting cooperative games you might also check out Space Alert, Lord of the Rings: The Card Game, and Mousquetaires du Roy (which is actually semi-cooperative).