My favourite has got to be:

"From where you're standing it must seem that you've had a 24-carat run of bad luck, truth is, the game was rigged from the start.."
*Tense crescendo*
*Kerblam!*

I'm interested to know what you (yes, you!), think are the most funny, clever, thought-provoking lines in the game, or even in other games in series.

Discuss.

Just gonna list off some for the sake of giving people some to work with:

"Thumbs down, you son of a [censored]!" - Boone

"We shall see how brave you are when nailed to the walls of Hoover Dam, your body? facing west so you may watch your world die." -Legate Lanius

http://www.youtube.com/watch?v=wgSHKQO3wi8&feature=related

"What are you doing here? You don't have clearance"
"I have clearance for catching spies." - The Courier

"The last thing you never saw" - NCR 1st Recon

"Better stop pointing that gun at me before I stick it up your ass."

"What are Flowers of Pock-Lips?" Courier