Fox and WB Offerings by Turns Soar and Bore

Like an Energizer Bunny, the new prime-time season keeps going ... and going ... and going.

By far the best of tonight’s four newcomers is Fox’s highly arresting “John Doe,” which follows the moderately appealing space western “Firefly,” from “Buffy the Vampire Slayer” creator Joss Whedon. And landing on the WB--opposite “John Doe,” unfortunately--is a promising comedy, “Greetings From Tucson,” along with an insipid one, “What I Like About You.” As if there were something to like.

“John Doe” generates excitement that recalls “24,” whose arrival on Fox last season wowed critics with a suspenseful format in which individual episodes represented one hour of real time. Remaining to be seen is whether “John Doe” is more successful than the unconventional “24” at sustaining momentum for an entire season (if granted that opportunity).

The show’s activity orbits mysteriously around a man (Dominic Purcell) who surfaces in Seattle naked, colorblind and with knowledge of every arcane fact imaginable. Doe is a human HAL. He knows the population of Morocco and the first line of “Macbeth.” He knows Gilligan’s first name, the number of bones in the human body and how many dimples there are in a golf ball. He barks out answers to TV’s “Jeopardy!” while speeding through crossword puzzles. He’s a phenom who knows everything about everything.

Except who he is.

Finding that out will be his focus each week, along with volunteering his unique gifts to help a friendly cop (John Marshall Jones) solve impossible crimes. It’s a stock TV scenario, but one driven by an intriguing character played by an actor with magnetism in a pilot that has Doe searching for a missing girl with whom he feels a curious connection.

Part of the fun is imagining what you would do if as all-knowing as Doe. The premiere indulges that materialist fantasy pretty effectively, as Doe buys a swanky loft, a fancy sports car and a GQ wardrobe with the fortune he makes from playing the horses. Yup, that would work. He can use his brain to cure cancer later.

Meanwhile, Doe takes a job as a musician in a bar. “It’s one thing to know the notes, it’s another to feel them,” he says while playing the piano gracefully.

He tells a guileless colleague he doesn’t know his identity. “No way,” she responds. Then she lights up. “You’re adopted?”

Droll humor is another reason to like “John Doe.” And what the premiere of “Firefly” strives for, but lacks, while introducing (not very clearly) a society 800 years ahead of ours. Fox calls “Firefly’s” characters “cowboys of the future,” and the series opens fittingly with a barroom brawl before getting on with business inside Serenity, a small, clanky, low-lit space freighter operated by cheeky Mal Reynolds (Nathan Fillion).

The frontier “Firefly” crosses is not new. You’re in the right galaxy if you’re thinking Han Solo.

One difference is that early “Firefly” lacks majesty, and also that its laborious pace is hardly Star Warsian. That’s so even when a homicidal criminal hires the cash-short Serenity’s crew for a cargo heist in the aftermath of a civil war between the totalitarian Alliance and independence-minded rebels like Mal and his second in command, Zoe (Gina Torres).

Also notably on board are the volatile mercenary Jayne (Adam Baldwin) and slinky Inara (Morena Baccarin). With prostitution now legal and even admired, she has her own shuttle docked in the Serenity.

The production look is interesting if unspectacular, and the characters have ambiguous appeal. If only “Firefly” would give them tasks worth watching.

America’s Latinos might as well be occupants of a distant star system given their near invisibility in prime time, thanks to TV programmers who define them as outside the U.S. mainstream.

That’s why “Greetings From Tucson” is welcome, even though its moving-on-up premise is a Mexican American cousin of “The Jeffersons” and some of its nicest lines are obliterated by a blaring laugh track.

Now there are two English-language Latino sitcoms in prime time, ABC’s “George Lopez” and this autobiographical one from Peter Murrieta, neither of which features stereotypical gangbangers or characters driving cars with fuzzy dice hanging from the rearview mirrors.

Like “George Lopez,” the WB series has middle-class values, as a job promotion allows Joaquin (Julio Oscar Mechoso) to move his Irish American wife, Elizabeth (Rebecca Creskoff), and their teenagers, David (Pablo Santos) and Maria (Aimee Garcia), into a solid suburb. Meanwhile, their neighbor exposes her bigotry when mistaking Joaquin and his brother, Ernesto (Jacob Vargas), for yard workers and telling Elizabeth they look “untrustworthy.”

“Greetings From Tucson” is from David’s perspective and has a good heart. Although Maria self-consciously identifies her family as “Spanish,” the series displays its Mexicana proudly, and is just witty and offbeat enough to stand out from the crowd.

“What I Like About You” is the crowd. It’s deeply rooted in decades of formulaic sitcoms--and pretty much a clone of the 1980s series “My Sister Sam”--with 16-year-old Hollie (Amanda Bynes) preferring to move in with her older sister, Valerie (Jennie Garth), than accompany her dad to Japan, where he has a new job. He says yes because a parent leaving a teenager behind is no big deal in this universe.

But here’s the problem: Hollie is a silly little kook, and Valerie is strait-laced. Hollie equals chaos and calamity; Valerie wants order, relishing peace and privacy after ridding herself of a roommate she disliked. Hollie turns Valerie’s life topsy-turvy, and Valerie will not stand for it, knowing that if her sister keeps it up, her career and social life will suffer.

Simple solution: Send the kid to Japan. But noooooo.

Get those hankies ready for sisterly blubbering. Blood turns out to be thicker than logic, and this unfunny live-in arrangement, with its emphasis on lame physical gags, appears destined to last as long as viewers will tolerate it. Which may not be long.

“John Doe” will be shown at 9 p.m. Fridays on Fox. The network has rated it TV-PGV (may be unsuitable for young children due to violent content).

“Firefly” will be shown at 8 p.m. Fridays on Fox. The network has rated it TV-PGLV (may be unsuitable for young children due to coarse language and violence).

“Greetings From Tucson” will be shown at 9:30 p.m. Fridays on the WB. The network has rated it TV-PGL (may be unsuitable for young children due to coarse language).

“What I Like About You” will be shown at 8 p.m. Fridays on the WB. The network has rated it TV-PG (may be unsuitable for young children).

Howard Rosenberg’s column appears Mondays and Fridays. He can be contacted at howard.rosenberg@ latimes.com.