Sheldon : "That lecture was a waste of time. I made more accurate diagrams of the expansion of the early universe on the nursery wall with the contents of my diaper."

Mary : "Hon, you think maybe the reason why you're having trouble finding a guy to settle down with is because you're letting them ride the roller coaster without buying a ticket?"
Penny : "Oh, they don't always get to ride the roller coaster. Sometimes they only get to spin the teacups."

Leonard : "You want some Oreos?
Sheldon : "Double Stuf?"
Leonard : "No, regular."
Sheldon : "Nice. Kick a man when he's down."

Sheldon : "My mother's fried chicken is why we had to buy my dad the extra large coffin."