Leviathan (1997)

If I tell you Leviathan is a cross between 'Go Fish' and a non-collectible 'Magic: the Gathering', you will instantly know pretty much everything you need to know about this game. Players take turns asking each other for cards matching the ones in their hands, each card being named after a particular fish (or fish-related being, such as Atlantean Priests or Mermaids). When a player manages to get a pair, they place it face-up on the table in front of them, just like in Go Fish. Once the cards hit the table, the Magic: the Gathering aspects come into play, as most of the fish have unique powers that can be used to aid you or annoy your opponents. There are also unique cards (with names like "Flying Dutchman" and "Offshore Oil Rig"), which have more esoteric powers and move from player to player as they get used. When one player runs out of cards in their hand, everyone scores a point for each pair they possess, and a new hand is dealt until every player has dealt once, at which point the final scores are tallied and a winner is declared. (Game time is thus dependant on number of players -- my guess of 90 minutes is a rough estimate of a 6-player game, which may not be at all accurate.)

In many ways, Leviathan epitomizes the "beer-and-pretzels" game -- in fact, it was designed in a coffee shop, out of a need for something to do while sitting in a coffee shop. The rules encourage a light ("jovially rude") atmosphere, and the writing style generally reflects this, although careful attention has been paid to the way the various cards interact, and to fix any possible contradictions or loopholes. (And the rule set has been edited to remove unnecessary rudeness in the author's writing style, although -- shh! -- an "impolite" version of the rules is rumored to exist, somewhere...)

Players are encouraged to devise new card powers and game variations, and as a bonus for players south of the equator, a special "Southern Hemisphere" option is given, which explains the way the Coriolis Effect changes the order of play.