Retief/YMMV

Crowning Moment of Funny: What most stories are made of.
Magnificent Bastard: Some of the Groaci.
Nightmare Fuel: Keith Laumer himself served in the United States Foreign Service, and his experiences no doubt influenced the Retief tales. One hopes that its just parody. However, as one person once noted "if the stories offer an accurate, rather than exaggerated, picture of terrestrial diplomacy it is rather worrying."
Unfortunate Implications/Fridge Horror: While it is doubtful that any specific incidents mentioned in the story actually happened in real life, Laumer came up with the concept of Retief due to his experiences while working for the US Department of State. If the diplomats he worked with really inspired the people Retief served under, it's a marvel anything gets done through diplomacy at all.