If you like The Office and Extras, Curb Your Enthusiasm will take you right to the source of improvisation based situation comedy.
Larry David is offended by many things and equally causes offence to many of the people he encounters. But the uncomfortable situations he faces are all too familiar to the viewer, it's just that most people would avoid rather than confront. Larry gets it out there to be dealt with, sometimes with success, sometimes (most times) not. Every time, however, the consequences are hilarious.
I am a huge fan of curb your enthusiasm and so far have bought series 1-4 and I would say that they are all as good as each other. No particular episode of this series stands out in my mind but I would say that they are all excellent. I decided to buy it because I had seen a couple of episodes on tv but they were of series 5 and I liked what I saw so decided to buy the rest.
If you only watch one comedy this year, make it Curb Your Enthusiasm, starring Larry David. His attitude to all of life's problems, although highly annoying, makes for great comedy. The nuances made, and the witty dialogue makes this a treat for any true fans of comedy.