Ho Yay: In the episode where Gary ends up accidentally splitting himself/cloning himself. The final Gary, "Good Gary", is gay, and starts to hit on Ron. If these are parts of Gary, you have to wonder what this implies about him.
Tear Jerker: The old and senile Reg Dedman and to a lesser extent the expression on Gary's face when he meets his grown up alcoholic son Michael in the 1990's and realizes that he had failed as a father by never being there for him.
Not one single constable or member of staff at his police station found the heart to turn up to Reg's retirement party even though he had been there for twenty five years. He was never well liked and he was incompetent, but to not even give him the traditional pocket watch that Reg mentioned was disgusting. You can see it on his face that he wasn't deluded enough to really believe that they had confused the dates. Leads to a Crowning Moment of Heartwarming when Gary tries his hardest to cheer him up.