Mafia II Easter Egg - Crazy Guy in Prison Yard

Go to Chapter 6 - Time Well Spent.

On your way to find Leo Galante you will come across a guy who is rambling. If you listen to him he spews quotes from the (in)famous Zero Wing; in fact all of his words are from the intro to Zero Wing, carefully worded to appear as if he is rambling about WWII which is when the game is set (well up until Chapter 7)

Phrases include:

War is Beginning
All Your Base Are Belong To Us
Someone Set Us Up The Bomb
You Have No Chance To Survive Make Your Time

It's a clever egg as while very obvious to All Your Base fans it fits with the environment so that if you're unaware you would just assume the character is a WWII solider turned criminal suffering from Post War Syndrome.