20/20

Is America Number 1? And if so, number 1 in what? Government? Economy? Culture? What makes a country prosperous? Democracy? The U.S. and India both have democracy, but only one is prosperous. Natural resources? Hong Kong and the U.S. are both prosperous, but only one is rich in natural resources. John Stossel argues that what makes a country prosperous is rule of law and economic freedom.

Greyhound Racing Showcased, Flip Wilson Interviewed, California Primary, Nuclear Bomb Report, 10th Anniversary of Robert Kennedy Assassination

Thomas Hoving examines the disco craze and visits Xenon in New York City; Jubilation in Las Vegas; Ones, a disco for children in New York City; the Empire Rollerdrome in Brooklyn; and a retirement/rehabilitation home in Los Angeles, where disco dancing is used as a form of therapy.

Parents spying on their children; Carnie Wilson talks about her surgery and career; Jane Pauley discusses her retirement from NBC and future endeavors; a teenage girl born without arms excels

Deborah Roberts takes a look at nepotism, and interviews with Donald Trump and his children Donald Jr., Ivanka and Eric, Andrew Firestone, Faye Dunaway and her son Liam, Cybill Shepherd and her daughter Clementine Ford, Dr. Phil McGraw and his son Jay, and Gov. Frank Murkowski, who appointed his daughter Lisa to his senate seat.

Topic: drugs in Hollywood. Interviewees include Jack and Kelly Osbourne. Also: Cynthia McFadden updates a 2007 profile of Daniel Baldwin.

A family slaughtered in their home, with only one witness left behind.

Men allegedly scammed by so-called "Military Mistress" speak out.

A family slaughtered in their home, with only one witness left behind.

Men allegedly scammed by so-called "Military Mistress" speak out.

Diane Sawyer reports in-depth look at Islam in America and around the world.

Remarkable medical conditions are showcased including children diagnosed with Williams Syndrome, families that must deal with Tourettes Syndrome and inside the mind of Daniel Tammet, one of the world's smartest people diagnosed with Asperger's.

Former Rutgers student, Dharun Ravi, sits down for his first interview since being found guilty of spying on his college roommate, Tyler Clementi, with a webcam in the fall of 2010 because he was gay; Ravi faces up to 10 years in prison.

With the Mega Millions reaching almost half a billion dollars, "20/20" looks at past winners and losers, as well as the con artists who want a piece of the winner's take; reports also on broke lottery winners, office pools, and playing the odds.

The stories of men and women from around the country who have dramatically transformed their lives by adopting new, healthier lifestyles and losing up to half of their body weight, and the impact it has had on their loved ones.

From tricks of the trade for saving money on nuptials, and "Groomzillas" to extreme wedding proposals and wedding mishaps, "20/20" provides viewers with a behind-the-scenes look at the cutthroat wedding industry.

Gypsy Willis explains why she moved into Martin MacNeill's home two weeks after his wife's death.

When a couple is found dead, the investigation leads to a woman they had a relationship with online, her family and a man who claimed to work for the CIA.

The murder trial of Tom Fallis, who was accused of killing his wife after her death was originally ruled a suicide.

Gio Benitez reports on the story of a 29-year-old lawyer who was found shot six times by his girlfriend in what she claims was self-defense, but a former girlfriend enlightens police with information that could possibly indict the current girlfriend.

A report on a child's life with autism.

A man found adrift at sea in a life raft claims his mother disappeared when their boat sank during an ill-fated fishing trip the two had embarked on.

Authorities set up an elaborate sting operation to catch a Houston couple who were allegedly attempting to hire a hit man to kill their exes.

The 2011 disappearance of a 20-year-old Tennessee woman and the ensuing investigation; interviews with the victim's family members and others connected to the case.

Following the life of Nathaniel Newman -- who was born with a cranio-facial condition known as Treacher Collins -- and his family.

Tito Jackson's ex-wife Dee Dee Jackson tragically drowns; Jackson family finds death of Tito Jackson's ex-wife suspicious; Dee Dee Jackson's sons won't object to mom's convicted killer being paroled.

Successful Houston veterinarian finds love again with younger doctor; Authorities set up an elaborate sting operation to catch a him after he convinces her they need to hire a hit man to kill their exes; Man speaks to 20/20 while he awaits trial behind bars.

Brother recalls the 2011 day he saw his sister, Holly, alive for the last time; Missing 20-year-old Tennessee nursing student Holly Bobo's remains are found by ginseng hunters; Jury returns with verdict in man's trial for Holly's murder.