Season 1 New York (1992): Julie Gentry befriends a homeless woman, spends the night in her makeshift community, Reagan-Ville.
Season 2 Los Angeles (1993): Tami Roman has an abortion.
Season 3 San Francsico (1994): Pedro Zamora struggles with AIDS and becomes an activist. He dies shortly after the season finale airs.
Season 4 London (1995): During a concert, Neil Forrester playfully kisses a drunken male heckler, who responds by biting his tongue.
Season 5 Miami (1996): The housemates listen outside the window as Mike Lambert has sex in the shower with a woman he picked up.
Season 6 Boston (1997): Montana McGlynn gets fired from the cast's after-school program after allowing a child to taste some alcohol.
Season 7 Seattle (1998): Stephen Williams slaps Irene McGee as she moves out. He is forced to take anger-management classes.
Season 8 Hawaii (1999): Ruthie Alcaide passes out after a drinking binge. Her roommates eventually persuade her to check into rehab.
Season 9 New Orleans (2000): Melissa Howard is upset when a tour guide uses the "N" word.
Season 10 New York (2001): Coral Smith is offended by Mike Mizanin's views on black people.
Season 11 Chicago (2002): Episode in which the cast learns about the Sept. 11 attacks is one of the highest rated in MTV's history.
Season 12 Las Vegas (2002): Trishelle Cannatella and Steven Hill, who refuse to use condoms, have a pregnancy scare.
Season 13 Paris (2003): CT Tamburello and Leah Gillingwater are caught submitting fake reviews for their jobs at Frommer's.
Season 14 San Diego (2004): Frankie Abernathy engages in self-mutiliation. She dies in 2007 from cystic fibrosis.
Season 15 Philadelphia (2004): Sarah Burke takes off her shirt and invites her new roomies to inspect her breast implants.
Season 16 Austin (2005): Johanna Botta lies that Nehemiah Clark got in a bar fight; Danny Jamieson runs outside and gets beaten up.
Season 17 Key West (2006): John Devenanzio thinks he's funny when he removes Jannelle Casaneve's bikini without her permission.
Season 18 Denver (2006): Alex Smith, Colie Edison and Jenn Grijalva share a three-way kiss. Edison later comes down with mono.
Season 19 Sydney (2007): Trisha Cummings and Parisa Montazaran compete for the affections of a guy named Alex.