The Office is one of the funniest TV shows on TV right now, or ever, even.
Although season 4 is shorter because of the writers strike affecting it, the double length episodes at the start of the season and the hilarious special features (especially the gag reel) more than make up for that.
I was lucky enough to purchase the Best Buy exclusive set of the DVD which includes the 'Fun Run Kit' (t-shirt, water bottle and wrist band).
All copies of the DVD no matter where purchased come with a free 'Dinner Party' script.
10/10