Only one for the record book
(I liked the sitcom when Hyacinth told Richard to "Mind the Cows" and "Mind the tree" to which he responded, "Minding the cow" and "Minding the tree")
book worm
(I think the mind the gap - wasn't so much the word mind as it was way it was announced; perhaps the tone and how clearly and loudly it was said - just struck me as funny).
hole in the road
(danon, you must be refering to hyacinth boo-KAY, not BUCK-et. didn't watch it myself, but heard bout it from a fan)