Here's a few from S-1 that made me laugh
"Love? Pah. Overrated. Here, look, these are my three
wives: Pestilence, Famine and Death. Do you think I
married them for their personalities? Their personalities
could shatter entire planets! Arranged marriages,
every one, but they worked out. They inspired me.
Knowing that they were waiting at home for me is what
keeps me here -- 75 lights years away."
-- Londo to Vir in "The War Prayer"
"Good morning. The time is o-four-thirty Earth-standard,
Wednesday, August third, 2258. Personal log shows no
outstanding appointments. Shall I download station-logs
for past six hours?"
"Sure, grab it, store it, shove it."
"Clarification?"
"Never mind. Why does my mouth always taste like old
carpet in the morning?"
"Unknown. Checking medical logs."
-- Computer and Ivanova in "Signs and Portents"
"I'm still waiting for an explanation, gentlemen."
"Yes, and I'm prepared to give you one, Commander, as
soon as the room stops spinning."
"This station creates gravity by rotation. It never stops
spinning."
"And you begin to see my problem."
-- Sinclair and Londo in "The Quality of Mercy"