While all four Halloween episodes of The Big Bang Theory were good, some were better than others for various reasons.
Sheldon Cooper allowed very few people to call him by a nickname. His mother and sister, Missy Cooper, referred to him as Shelly. His grandmother, affectionately known as MeeMaw, called Sheldon ...
Over the course of 12 seasons, there were occasionally plotlines on "The Big Bang Theory" that were abandoned with no reason given.