I found the official website listing for custom license plates in my state, but someone already has COMSTOCK. Not that it really matters to me, but it'd be fun for about two minutes. Then you get road rage and it no longer matters.
Also, I figured a fun way to annoy a BioShock fan:
"Hey, those nudes of your GF were awesome. Thanks for sending them."
"What are you talking about you starfish?"
"Your nose... it's bleeding..."
Not perfect, but you get the meaning.