TONIGHT'S MUST-SEE

"American Idol," 7 p.m., Fox. The finale draws a huge audience each year. We can expect Fox to fill most of the two hours with fluff. That includes the return of the people in the top 12; some guest stars; and lots of hype, lots of hustle, lots of promos. Then we'll learn whether the new champion is the talented Jordin Sparks or the charming Blake Lewis. That's important, because many winners (and some losers) have gone on to big things.

"Lost" season finale, 8 p.m., ABC. With a gun-wielding attack expected, the survivors have planned an ambush, complete with hidden explosives. Also, last week, Charlie made a dangerous swim to an underwater ship. He got there, only to face some armed women. Much of this remains confusing, but there may be some turning points tonight. We get warfare, complications and some more flashbacks with Jack.

OF NOTE

"Saturday Night Live in the '90s," 7 p.m., NBC. The first "SNL" documentary was a wonderful view of the early years, recalling extremes of genius and decadence. This third one doesn't come close, but it has clips from a lot of funny sketches. It savors the years when an expanded cast left lots of talent (Farley, Rock, Myers, Sandler, Carvey, Silverman, more), some of it underused.

"Lost: The Answers," 7 p.m., ABC. Here's a slightly longer version of the special that aired last Thursday.

"Hustle," 7 p.m., AMC. The season ends with an hour that makes up in dazzle for what it lacks in logic. Retaliating against violence, the team wants to pull an impossible heist inside a Las Vegas casino. Pulling it off requires extreme luck and coincidence. If you can overlook that, then this is a fun, flashy episode.

"Secrets of the Dead: Voyage of the Courtesans," 8 p.m., PBS. In its early years, this excellent documentary says, the Australian prison colony desperately needed women; a shipload of female prisoners was sent from England. Many of the women had been imprisoned for the mildest of crimes. They would become important pioneers of a new nation. Along the way, however, some saw the journey as a chance for prostitution.