I think the one where Peter Jurassik is reading the road map is a classic, and I love a bunch of the others already mentioned. A couple that haven't been:
Londo and Garibaldi in the bar, discussing Centauri ducats:
Londo: Cen-TAR-ay?
Garibaldi: Cen-TOR-ri
Londo: To-MAY-to?
Garibaldi: To-MAH-to
Both (singing): Let's call the whole thing off...
***
Lennier nose-to-nose with Ashan (the Minbari who tried to frame Sheridan in "There All the Honor Lies"):
Ashan: You may ask your questions.
Lennier: Who carved your bone? 'Cause it's fabulous the way he ---
Ashan: Same guy! Same guy! He just has this new thing he's doing where...
***
And one I can't believe no one has mentioned:
I think this one is from "Soul Mates." It is a crowded reception, the EarthForce regulars are in dress uniform. Someone (Londo, I believe) has just collapsed and is lying on the floor as people crowd around. Bruce Boxleitner, playing the take-control Captain, steps forward, assesses the situation, keys his link, and utters the immortal line:
"Medlab. This is
Sinclair."
Needless to say everyone in the scene (including the "dying" Londo) lost it, and someone (either Netter or JMS, I think) walks into the shot and appears to hit Bruce with a rolled-up script.
Regards,
Joe
------------------
Joseph DeMartino
Sigh Corps
Pat Tallman Division
joseph-demartino@att.net