When Spock mentions "hot pursuit" in regards to chasing the Gorn in Arena
. Cracks me up everytime!
"Hot pursuit" (at least in the 21st century) is a legal term to indicate a status in which some police actions may be lawful that wouldn't be otherwise, such as pursuit outside an officer's jurisdiction. So it's logical that Spock would want to document that status in the Captain's Log.
These lines come to my mind at the moment:
And just about any of Spock's lines in "That Which Survives." Struck entirely the wrong tone.
Maybe, I'd have to watch it again...but the look on his face when Scotty says, "It's stuck!". Pure, marvelous acting. His face falls just the right amount for a Vulcan.