I'm an ATC at Cleveland Center in the US. Over the last 13 years, I've had a few laughs, but the funniest situations are when the pilots work with you...
B757: Cleveland Center/UALXXX on you, FL390.
Me: UALXXX, roger.
HS25: Cleveland/HawkerXXXX checking in, FL370 looking for FL390.
Me: HawkerXXXX, roger. Traffic 3:00, 40 miles, FL390, a 757. Higher in about 6 minutes.
(about 2 minutes later)
HS25: HawkerXXXX looking for FL390.
Me: XXXX, your traffic is now 3:00, 25 miles, FL390. Higher clearing him.
(about 30 seconds later)
HS25: Center, how's 390 looking?
Me: HawkerXXXX, say ride conditions (thinking he was getting a rough ride).
HS25: Smooth.
Me: HawkerXXXX, if I climb you now, you'll be the hood ornament on a 757.
B757: Center, we're not configured for a hood ornament.
...thanks again to that 757 pilot, whomever you are