Michelle Obama appeared in the South Park episode, "About Last Night", as Barack Obama's wife and conspirator.
History
Michelle and her daughters are revealed to not be truly family to Obama, but rather a cover that was designed to give him a proper 'family' look while running for president. Although she is obviously a loving mother, Michelle is a computer hacking genius hired to help Obama and John McCain steal the hope diamond.
After succeeding in the heist and faking their deaths, Obama decided to give being president a chance and asks Michelle to be a real family, and be his first lady. Michelle agrees by kissing him passionately after saying "oh what the fuck?"
Michelle appears again in a non-speaking role in Sexual Healing.