TONIGHT'S MUST-SEE

"American Idol," 7 p.m., Fox. Last week, Brooke White was voted out and Syesha Mercado had another scary time in the final two. Meanwhile, the three guys — David Archuleta, David Cook and Jason Castro — watched comfortably. "Idol" seems headed for a duo-David finale, but tonight — with a Rock & Roll Hall of Fame theme — comes first. Can Mercado belt her way out of trouble? Can Castro boyishly grin his way? We'll see.

"Shark," 8 p.m., CBS. Last week's terrific episode spun Stark's world inside-out. A sharp prosecutor promised he would keep his law license if he helped nab a killer. He did; her boss reneged. So Stark is in Nevada, where he's still licensed. Still a prosecutor at heart, he's reduced to defending a sleazy mobster. If this is anything like the last episode, it's worth catching.

OF NOTE

"NCIS," 7 p.m., CBS. Searching for a serial killer, Ziva is in danger.

"According to Jim," 7 and 7:30 p.m., ABC. In the first episode, Andy is sure Emily will leave him on their six-week anniversary. In the second, Cheryl is pregnant, bed-ridden ... and maybe cheating on game night.

"Saturday Night Live," 7:30 p.m., NBC. Here are 90 minutes of Molly Shannon clips. That may exceed our interest by 87 minutes or so.

"American Experience: George H.W. Bush" conclusion, 9 p.m., PBS. At his peak, Bush had an 89-percent approval rating; at his low point, he failed to be re-elected. He was attacked on the right for breaking his no-new-taxes pledge, on the left for a stumbling economy. This fond portrait offers a gentleman politician, quietly doing what he felt was right.

"Law & Order: Special Victims Unit," 9 p.m., NBC. Stephen Collins usually plays nice guys, which suits him. Here, by comparison, he heads a rich, ruthless family.

"Women's Murder Club," 9:02 p.m., ABC. A woman says she was raped by two drunken college guys. Soon, there's a revenge killing and one of the "club" members is in jeopardy.