Best party card game I know is one I learned at school. I was never told the name for it, so we subsequently named it "Spank the Monkey."
Players sit in a circle around the table. The playing deck consists of a set of four cards of the same rank for each player; so for a six player game you might have four aces, four fours, four kings, and so on for a total of 24 cards. The play deck is shuffled and dealt, four cards to each player, and the remaining cards are placed in the middle of the table to form the "losing deck".
The object of the game is to get a hand of four cards of the same rank. To do this every player simultaneously places a card on the table for the player to the left. So as you pass a card, you should be receiving a card from your right at the same time.
Take the card, add it to your hand, then rinse and repeat passing another card to your left and so on.
At some point, someone will make a hand of four identical cards (or maybe more than one person will). They declare this by placing a hand on the losing deck. Everyone else must then place their hand on top of the first one down. The last person on top is the loser of this round.
The loser receives a card from the losing deck which they put aside; it is used as a score marker only and not shuffled into the playing deck. The playing deck is collected and shuffled, then re-dealt for the next round (it's nice to rotate dealers each round). Play continues in this manner until the losing deck has all been allocated, at which point everyone's losing cards are counted up and the person with the fewest is the winner.
It is verboten to touch the losing deck during game play unless you have a winning hand of four (or you're on top of someone else's hand in normal play). Bluffing is therefore encouraged, pretending to move for the deck in order to trick someone into jumping in first. Should someone touch the deck inadvertently, they receive a bonus losing card (to put aside) and play continues.
Typical play starts off civilised, and gets faster and more hectic (and chaotic) as people get involved and excited about it and start slamming hands in. It's a brilliant, brilliant game for all ages, though delicate young fingers and the ham fisted is a combination probably best avoided. (-: And, you might want to call it The Other Game With No Name.
Oh yeah - and don't use a deck you care about - some people have a habit of going for the losing deck with cards in their hand so you might end up with a few mangled cards. I have an ancient deck I used exclusively for StM; doesn't matter if there's a few cards missing from it.
(Incidentally, I'd love to know a) if anyone else has ever played this or if it's an entirely local invention and b) what the hell it's actually called!)