I'd like to give a plug for playing bridge. It is the best card game there is. Texas Hold 'Em : Checkers :: Bridge : Chess.
It can be a sociable game and yet it can also be a game that holds you interest as you try to achieve perfection.
To anyone who wants to get started there is a bit of learning curve. There are good guides online, computer games to help practice with (Bridge Baron is good and is even available for the iPhone), and there are local clubs that would love to see you come out (check out ACBL).