Lately, the cold openers have been hit or miss, but always tending to be goofy in the punch line. An example of a bad cold opener was last week's episode (The Sting), wherein Michael was portrayed as being so dumb that he never learned to ride a bicycle.
Halloween episodes are fun to watch. The costumes are always interesting, whether it be Jim's minimalism, or Creed's incredible uncanniness. But with The Office tradition, something tragic always happens at that time of the year.