"Swear words always sound more terrible in your native language"
The Bulgarian word пък
"Translation is a necessary evil"
Tolkien pretending to be a translator of Lord of the Rings
The Noh play Matsu Kaze (whose title is a delightful pun that the official English translation mangles horrible. "Wind in the Pines"? No, you idiots, it's "Pine Wind" or "the Wind Pines" if you want to get all James Joyce-y)
Japanese puns like Hashi de kita
"Putting a hat on it" or "hanging a lamp shade on it" if you actually know what you're talking about
Allo Allo and its use of accent