londo has great lines right from the get-go:
varner. del varner
my god, man, we've become a tourist attraction. see the great Centauri Republic: Open 9 to 5 - Earth time.
My favorite Londo line from "The Gathering":
"You're a security chief, shouldn't you be securing something?"
And, of course, Garabaldi's response:
"I am. I'm securing you."
From that first moment, I knew that I was going to like Londo.