TONIGHT'S MUST-SEE

"Saturday Night Live Presidential Bash 2008," 8 p.m., NBC. In this remarkable year, everything involving the election has drawn huge ratings. That includes conventions, debates and "Saturday Night Live." Now "SNL" gets one final shot, blending this year's political sketches with past ones. Some old ones (especially Dan Aykroyd as a cranky Bob Dole) were strong. Others (Chevy Chase as a clueless Gerald Ford) were just silly fun. This year, under writer Seth Myers, there's been more punch. We've seen an overconfident Hillary Clinton, a catered-to Barack Obama, a meandering John McCain, an out-of-her element Sarah Palin. In other words, it's "SNL" at its best.

TONIGHT'S MUST-TAPE

"Frontline: The Choice," 9 p.m., PBS. Laughing at politics is a healthy part of democracy. Still, here's a helpful counterbalance. Every four years, skeptical "Frontline" views the candidates. This rerun, with deep reporting, seems to conclude that these are two fine people.

OF NOTE

"Big Bang Theory," 7 p.m., CBS. The guys seem startled by the presence of any lovely woman near Sheldon. In last week's rerun, it was his twin sister; now it's a grad student.

"Worst Week," 8:31 p.m., CBS. Sam finds new ways to get in trouble. Tonight, he's watching his fiancee's niece ... who swallows the precious ring given to them by a grandmother (Olympia Dukakis).

"First Class All the Way" debut, 7 p.m., Bravo. Here's the simplest of reality shows — pretty people living well. Sara Ryan Duffy, the prototype for all Irish beauty, is a travel planner who arranges a Monaco trip with friends. It's sort of fun to watch, except when an aide weeps because she might not fit in.

"Raising the Bar" season finale, 8 p.m., TNT. There's trouble on all sides for hard-nosed Judge Kessler. A higher court overturned her ruling. Also, she's still coping with the fact that Charlie, the aide she lusts for, is gay.