Coupling (The original British one, think they re-wrote it for America) it's about a group of thirty something friends and it is soo brilliant. Theres one episode where they are talking about "Whistling" (they are using as a euphemism for masturbating) when one of the characters parents come over and overhear a conversation about whistling, there is a brilliant bit where the father delivers a line, talking about whistling, unaware that they were using it as a euphemism, where he goes "You just put you're lips togeter and pucker."
And of course, who can forget the Spiderman Dance.