Great, great... the list is coming along. Keep recommending/seconding and we'll have a nice little collection of culture here. So far the only movie I've seen on the list is Taxi Driver which is certainly a classic and referenced all over the place. I've also read one of the books and seen only one TV show. Keep 'em coming!
"Join the Cult of Frank / And you'll be enlightened"
Fahrenheit 451 by Ray Bradbury. Censorship and governmental control gone mad.
Film
Jean de Florette - Gallic masterpiece and beautifully shot. The subtitles are forgotten after a few minutes. The story slowly meanders towards tragedy that you never really expect. Human greed versus human endeavour.
TV show
I second The Office. Also would suggest Steve Coogan's 'Alan Partridge'. Tightly scripted and carefully rationed comic gems.
"Join the Cult of the Theremin / It's Velouriatastic!!"
I second The Big Lebowski; I don't think any film will ever match the entertainment value of its dialogue. Almost to the point where I feel like I would want to watch it twice in a row just to laugh.
For another book, I think my favourite is Bend Sinister by my favourite author Vladimir Nabokov. Every time I read it I decide it's about something different, and I'm starting to wonder whether it's really about anything at all. The wordplay, is stunning - this is typical of Nabokov. One of my favourite features of this particular novel is that I can pick it up and just start reading from any chapter and still get something meaningful without relating it to another part of the story. I find that very impressive - that each part of the book is strong enough to stand on its own. I wish there were more about which I felt the same way; some books are simply too cumbersome for me to finish.