In Series I, Episode 11 "Infantile", a question regards how long should the perfect hug last. Inevitably, everyone started hugging everyone else and it was actually rather sweet.
In Series B, Episode 12, Alan doesn't want to do a round of General Ignorance because he always gets them wrong and doesn't want to look like a fool on Christmas. Cue Stephen giving him the host's chair and getting nearly every question wrong.
In series D, Episode 6, Alan wins his first episode. Cue delighted expression from Alan and Stephen saying how proud he was.