Tonight Barbara Walters presents “The 10 Most Fascinating People of 2008” (9 p.m., ABC), an annual exercise in news chatter and celebrity journalism. This year’s crop includes Will Smith, Tina Fey, Tom Cruise, Miley Cyrus, Frank Langella, Rush Limbaugh and Olympic swimmer Michael Phelps.

Even if we grant Barbara Walters her right to bestow “fascinating” on whomever she chooses, you’d think she’d have to prove why someone happened to be fascinating in 2008, as opposed to all of the years he or she didn’t make the list.

It has been Olympic champion Michael Phelps’ year. He’s remarkable, but does that make him fascinating? The discipline and endurance that enables you to spend years training in a swimming pool does not always make for sparkling conversation.

And Rush Limbaugh must fascinate somebody. But what did he do in 2008 that stands out? Why didn’t Barbara interview him in 1994, when he seemed to have more clout? And what’s made Tom Cruise fascinating in 2008?

It be nice if Walters tossed a bone to a scientist, inventor or philosopher or author and introduced us to someone we’ve never heard of, someone truly fascinating.

• At the other end of the “news” food chain, Christiane Amanpour hosts “CNN Presents: Scream Bloody Murder” (8 p.m., CNN) a sobering two-hour look at genocide in the past century.

When faced with the history of genocides, people often reflect, “If we only knew.” According to this harrowing special, we almost always knew and did nothing about it until it was too late.

Holocaust survivor Eli Weisel claims the Allies were aware of the Nazi policy of extermination but chose not to bomb the railroads that brought victims to the death camps. “It was not a priority,” he explains.

The grim litany continues with recollections of Cambodia, Bosnia, Kurdistan, Rwanda and Darfur. In each case we hear from idealists who sounded the alarm only to be ignored or told that intervention was politically impossible.

After 10 years in Vietnam, what could Americans have done in Cambodia? Who could have averted Rwanda? Who does the responsibility for Darfur belong to?

On the other hand, some make a strong case that overlooking Saddam Hussein’s genocide against the Kurds in 1988 only emboldened him to invade Kuwait in 1990, resulting in two expensive wars. And former diplomat Richard Holbrooke argues that earlier military action against Serbia could have avoided countless deaths. Sometimes, Holbrooke and others argue, doing the “right” thing can be in our vital national interest.

Tonight’s other highlights

• A friend too close to nature on “My Name is Earl” (7 p.m., NBC).

• Betty must cooperate with Amanda on “Ugly Betty” (7 p.m., ABC).

• A repeat look at “Fat Pets” (7 p.m., Animal Planet) leads into “World’s Ugliest Dog Competition” (8 p.m.).

• A windfall sparks debate on “The Office” (8 p.m., NBC).

• The new series “Could You Survive?” (8 p.m., Discovery Health) challenges people to see if they could endure an emergency situation.

• Liz’s recollections are challenged at her high school reunion on “30 Rock” (8:30 p.m., NBC).