You've Got a Friend

You've Got a Friend was a short-lived, hidden camera reality comedy series where if contestants pass off an obnoxious fake friend as a real pal for two days without admitting the truth to anyone, they'll win $15,000 in cash.

(Keep in mind that this should not be confused with the classic 1971 James Taylor song of the same name)

Premise
The show filmed contestants having to tolerate a "friend" for 48 hours, while filmed on hidden camera in their home and different public settings. The "Friend" would be a trained improvisational comedian, who would progressively torment the contestant, their friends and loved ones. The catch was that friends and family of the contestant were unaware of the folie a deux ("Madness of Two"). If he or she is able to endure the embarrassment caused by the irreverent demands of the friend, the contestant would win a cash prize of $15,000.

Link
Official Website (via Internet Archive)