The oddly stylized "Beekeeper and Borg" fantasy is a frame for frame takeoff of the opening credits to the Diana Riggs era "The Avengers". That 1960s British spy spoof introduced us to one of tv's first kickass females, Emma Peel.
When Niles sends Dorothy to get dark chocolate, it echoes his obsession with candy bars in the Morrison era of the comic books.
When Cliff is saying goodbye to Clara in the garage, he starts singing The Living Years by Mike + the Mechanics.