Had to be when One-Two slaps Russian #1 after that long chase, and looks up triumphantly, only to see Russian #2 sheathing his knife.
shareLenny falling backward in his chair as he sees the painting is missing.
shareArchy's improvised reaction, after Lenny blames him for losing the key to the safe...
shareHands down - Archie's little "song" about missing teeth and his obvious delight over the microphone, including a quick gleeful smirk, then right back to classic tough-guy face! (while intimidating the producers for Johnny's whereabout's)
I rewound that approximately 12x laughing harder each time!