Decisions, decisions, decisions. Television critic Mike Hughes will help you look at tonight's viewing options, but leaves you with a choice to make.

TONIGHT'S MUST-SEE

"Castle" (ABC) or "Saving Grace" (TNT), both 9 p.m.

Take your choice, with crime stories that add character twists.

"Castle" (actually starting at 9:02 p.m.) is the fun one. In last week's opener, an ego-driven crime novelist (Nathan Fillion) worked with a tough cop (Stana Katic). Now he's patterning his new Nikki Heat character after her, while they probe the murder of a nanny.

"Saving Grace." which is on at 7, as well as 9 p.m., is dead-serious, with Holly Hunter superb as an Oklahoma City cop who is intense, alcoholic -- and often visited by Earl, her guardian angel.

Tonight, we finally learn the background of Abby (Christina Ricci), her temporary partner. Also, Bobby Stillwater, Ham's old partner, resurfaces after long undercover duty.

There are many things going on here -- so many that tonight's case (slayings in a drug-troubled neighborhood) -- is disposed of rather abruptly.

TONIGHT'S MIGHT-SEE

"Chuck," 7 p.m., NBC.

An all-rerun night for NBC starts with a typical "Chuck" episode, for good and bad.

The bad news involves the sub-plots, which are lame. At the Buy More store (Chuck's day job), Lester struggles as the new assistant manager; Morgan -- secretly in love with Chuck's sister -- sabotages her date.

The good news involves the main story and Chuck's duties as an undercover spy. He must charm the Black Widow; first, he gets lessons from an old spy (John Larroquette) who considers himself a great ladies' man.