Based on rummy, bamboozled is the best card game you never played.
You'll want a standard 52-card deck, along with two jokers (if you don't have any, you can play without). The game is best played with two players.
Object of the game
The object of the game is to score more points than one's opponent.
Play
Each player is dealt seven cards. The player who goes first alternates every hand. One card is placed face-up on the stack. Each turn a player must draw either from the deck or the stack (a player may take any card he likes from the stack, but he must use it on the same turn and take all cards on top of it).
A player may place any pairs (e.g. 4♥4♦) or suited connectors (e.g., 8♠9♠) face-up on his side. After placing down any combination, a player must show his hand.
At the end of the turn, the player must discard a card, adding it to the stack. A play in which there are no cards to discard is illegal.
The game is over when a player discards his last card.
At any point during the game, a player can "bamboozle" his opponent's cards to make his own combinations. He can take all cards that continue the combination, but not other attached cards (e.g., 4♦ can take opponent's 4♠4♣5♦6♦, but not 6♣ ).
If a player plays a pair of jokers, he may see his opponent's hand and take one card from it. The joker cannot be bamboozled.
Rapping the table
If a player discards a card that could have been played on cards already on the table or plays a card that could make a combination with the stack cards, the first player to rap the table twice gets the cards. It is possible to bamboozle with this card. The normal rules for taking from the stack are ignored. This card does not count as a draw. The player who discarded the card may not rap the table.
Scoring
At the end of the game, the value of the cards in a player's hand is subtracted from the value of the cards he has played on his side to find the score (Jokers are a special exception—see below).
Value
The joker
Unlike every other card, the joker is worth positive points in the hand—+10. Jokers on the table have no value.
The player with the most points wins. The game can also be played in a series to reach a set number of points à la Rummy 500.