Tonight's must-see TV is all new, according to television critic Mike Hughes.

"SAVING GRACE" SEASON-OPENER, 8 P.M., TNT

Grace's shaky life is in transition again.

Her former police partner (and frequent lover) has been assigned another partner. Grace (Holly Hunter) is working with a newcomer (Christina Ricci) who seems timid and overwhelmed -- at first.

Then there are the usual problems. Grace is the only TV cop who has regular talks -- arguments, often -- with her guardian angel.

Tonight's case -- involving the murder of blondes who have had plastic surgery -- is so-so. But the character portraits are rich and fascinating.

"LATE NIGHT WITH JIMMY FALLON" DEBUT, 11:37 P.M., NBC.

Jimmy Fallon is new at this, but he's upbeat, uptempo, enthusiastic. He's a sometimes-musician who has hired hip pros -- the Philadelphia group Roots -- as his house band. And he shares one thing with Johnny Carson and Dick Cavett of olden days: He's a boyish-looking guy; viewers will forgive him almost anything.

For this opener, he has Robert De Niro, plus music from Van Morrison.