NBC (Tuesdays, 9 p.m. ET)

NBC's recent announcement that Frasier (now in reruns) will inherit the coveted Seinfeld time slot next fall (Thursdays at 9 p.m. ET) was a welcome one. Bravo, as those erudite Crane brothers, Frasier and Niles, would no doubt say. But for diehard fans of the departed New York Four, a caveat: The Seattle Seven (pictured above) may not be your cup of latte. Frasier is a comedy of manners (its zingers drolly delivered, many with literary references), whereas Seinfeld, with its loud if lovably crass ensemble, was more of a comedy of bad manners.

That said, Frasier did manage to commit a few egregious faux pas this past season, its fifth. A date-swapping bedroom farce set at a ski lodge reduced the characters to frantic cartoon figures. The 100th-episode visit to the real Seattle (where Frasier is set) was padded and pointless. But the show delivered when Roz (Peri Gilpin) did: Her season-long pregnancy ended with a tender labor-room scene, as Frasier (Kelsey Grammer) cradled her baby. And the Niles-Daphne romance, heretofore just a big tease, got a good jump-start when the shy shrink (David Hyde Pierce) and his British maiden (Jane Leeves) finally sat down to a quiet dinner à deux. It's just one more sign that this witty sitcom is maturing nicely—and will make new friends on Thursdays.

Bottom Line: A witty, worthy successor to Seinfeld

PBS (Wed., June 17, 9 p.m. ET)

Show of the week

"How do you know when you're finished?" a TV interviewer once asked Alexander Calder about his kinetic, often cryptic, free-form sculpture. "When it's dinnertime," cracked the taciturn Calder. This American Masters profile of the artist (who died in 1976 at 78) shows him to be not only self-effacing (to deflect criticism, he referred to his pieces as objects rather than art) but also eccentric ("He didn't own a suit; he had two wool red shirts—and that's what he wore," recalls a friend) and astoundingly prolific. Besides creating his signature wire-suspended mobiles and monumental steel stabiles (some as high as seven stories), the Pennsylvania-born Calder churned out jewelry, posters, wood carvings and tapestries; designed stage sets for Martha Graham; choreographed a 19-minute ballet; and even painted two DC-8 jets in brightly swirling patterns for Braniff Airlines.

But the most revealing segment of this incisive documentary shows Calder, at 55, as the boyishly enthusiastic ringmaster of his own circus, playing with his wire-sculpted miniature elephants, acrobats, even a knife thrower. "With the circus he was in his element. He was a big kid," says his friend, playwright Arthur Miller. Still, the bemused audience in Calder's Paris flat in the 1920s included a who's who of modern masters, including Cocteau, Miró and Mondrian (whom Calder called a major influence on his art).

This hour captures the boundless optimism and energy of its subject. Or, as Miller says of a typically playful Calder mobile, "You just feel better for having stared at it."

Bottom Line: A superb tribute to a perennially youthful old master

TBS (Sun., June 14, 9 p.m. ET)

If it's real-life Baywatch babes you're searching for in this one-hour documentary, don't bother. Still, like the hit syndicated series they inspired, L.A.'s lifeguards—about 600 strong—are indeed heroes. Last summer they saved some 14,000 Angelenos from drowning. (They also reunite lost kids with their parents and shoo drunks off the beach.) But of the 100 or so guards who work year-round, only two are women. One quips that if she tried to swim in the sort of clingy suit worn by her TV counterparts, "it'd probably fall off before I even got in the water." She and the other full-and part-timers profiled in this low-key report are an engaging bunch who clearly love their jobs—especially Paul Silka, a lifeguard who doubles as an emergency room M.D. at Cedars-Sinai hospital. ER meets Baywatch? Sounds like a series.

Bottom Line: A breezy day at the beach

Nickelodeon (Sun., June 14, 8 p.m. ET)

Steven Burns, the Mister Rogers-like host of this weekday children's series, turns up in prime time to throw a birthday party for his cartoon dog Blue. Burns may be a soothing (and crooning) presence to his preschool audience. To this grown-up, however, he comes off like a hyperactive camp counselor. Far less resistible is Blue, a frisky yet winsome canine who, after opening a present from her viewers—a tiny blue toy dog—trots up to us and licks the screen. Awwww.

Bottom Line: Puppy love at first sight

Sci-Fi Channel (Mondays, 9 p.m. ET)

The premise of this adventure series (which slid off the FOX network in 1997 after three seasons and resurfaces this month on the Sci-Fi Channel with 22 new episodes) has always struck me as a lot niftier than its execution. Jerry O'Connell (Scream 2), Cleavant Derricks and Kari Wuhrer return as dimension-tripping travelers who wander from one parallel Earth to another. Each is weirdly different from our own: religious fundamentalists prevail in one world, Internet junkies rule another, drug pushers infest a third. Yet there is a tiresome similarity to the plots: In almost every episode our plucky heroes are captured by the reigning totalitarian regime only to be rescued by the local resistance group.

Conspicuously missing is John Rhys-Davies, who played Professor Arturo, the bombastic yet charismatic mentor to physics whiz Quinn (O'Connell, who's also a producer). Rhys-Davies wanted out, so Arturo was killed off. Bad move. But hang tough, Sliders fans. Among the new wrinkles this season: Quinn learns he has an older brother, Colin (played by real-life lookalilke younger sib Charlie O'Connell, who joins the cast in July). This week, though, it's still the same old story, as the Sliders are imprisoned by Nazi-like humanoids called Kromaggs, holdover villains from last season. Not to worry, though: Our heroes quickly get sprung by...Vive la Résistance!

Bottom Line: Game cast battles lame scripts

Terry Kelleher is on leave.

>Sunday, June 14 AMERICA'S GREAT PARKS Discovery Channel (8 p.m. ET) James Brolin leads a TV tour of the Grand Canyon, Yosemite and Yellowstone.

Monday, June 15 ROBERT DOWNEY JR.: THE E! TRUE HOLLYWOOD STORY E! (8 p.m. ET) A TV bio that includes the actor's recent drug trial and his stint in stir.

Tuesday, June 16 AFI'S 100 YEARS...100 MOVIES CBS (8 p.m. ET) Jujyfruits, anyone? Richard Gere and Jodie Foster host a three-hour retrospective of the greatest American films ever.

Wednesday, June 17 SPIN CITY ABC (8 p.m. ET) Maria Maples shows she's fit in this rerun about the mayor's aspiring lover.

Thursday, June 18 DIAGNOSIS MURDER CBS (9 p.m. ET) "Must Kill TV" is a must-see repeat about the slaying of a network TV exec.

Friday, June 19 REMEMBER WENN AMC (10 p.m. ET) This spoofily nostalgic series set at a '40s radio station begins a fourth season.

Saturday, June 20 FACE TO FACE: LIVE IN VIENNA HBO (9 p.m. ET) Piano men Billy Joel and Elton John find harmony in a three-hour-plus concert.