Leonard: What am I doing in your spam folder? Sheldon: I put you there after you forwarded me a picture of a cat playing the piano entitled, "this is funny."
Sheldon: Roommates agree that Friday nights shall be reserved for watching Joss Whedon's brilliant new series, "Firefly." Leonard: Does that really need to be in the agreement? Sheldon: Might as well settle it now; it's going to be on for years.