Your local television editor is going to do something he's never done before. He's going to beg and plead with you to watch a show tonight.

Please, please, pleeeeeease watch Northern Exposure (9 p.m., Ch. 5).Now, I'm only doing this because this is one of the truly great shows on television today. And I wouldn't want you to miss it.

It's from the folks who brought us "St. Elsewhere" and "A Year in the Life," neither of which ever drew the audience it deserved.

Like those shows, "Exposure" is full of well-drawn characters who ring true. A little offbeat, yes, but the kind of people you'd like to spend time with and get to know better.

"Northern Exposure" is built around Dr. Joel Fleishman (Rob Morrow), a New York native who couldn't afford medical school so the state of Alaska paid for his training. In return, Joel promises to practice in the northern state for five years.

But he received quite a shock when the series premiered this past summer. Instead of practicing in a modern, well-equipped hospital in Anchorage, Joel ended up in the tiny town of Cicely (population: 839), where's he's not only the only doctor but as an urban New York Jew he's wildly out of place.

"Exposure" isn't a medical show - it's a fish-out-of-water comedy.

We're not talking sitcom here, though. This is not full of one-liners and contrived situations.

The humor, which ranges from gentle to hysterical, comes from the interactions between the characters. It's witty, it's intelligent . . . in other words, it's on a considerably higher plane than most television.

All of the great characters who filled the show last summer are back - Maggie (Janine Turner), the bush pilot/landlady with whom Joel has a love/hate relationship; Maurice (Barry Corbin), the bombastic millionaire/ex-astronaut; Ed (Darren E. Burrows), the seemingly naive, often surprisingly wise 19-year-old Indian; Holling (John Cullum), the 62-year-old former big-game hunter who runs the local dining establishment along with his 18-year-old girlfriend, Shelly (Cynthia Geary); and Chris Stevens (John Corbett), the free-spirited deejay and philosopher.

If you were a fan last summer, it's great to see these characters again. But even if you've never seen "Exposure" before, you can pick it up tonight and enjoy it just as much.

And in this return episode, Joel gets a "dear John" letter from his fiancee in New York - turning him into even more of a self-pitying whiner than usual. And when Holling adds a satellite dish, Shelly turns television addict in a big way - watching everything from Puerto Rican soap operas to "Magnum P.I." in Japanese.

It's a lot of fun. So please, please, pleeeeease tune in.

Hollywood Detective (8 p.m., A&E), on the other hand, is a major disappointment.

Filmed here in Salt Lake City, it's the story of a private eye/aspiring screenwriter (Tony Peck) in - you guessed it - the Hollywood of 1931.

It's trying hard to re-create the spirit of those old '30s detective movies - too hard. It's pompous, over-written, underacted and just not much fun to watch.

Tonight's mystery involves a movie screenplay purportedly written by F. Scott Fitzgerald (Ian Buchanan). Of course, Scotty can't remember writing it (he was a drunk, you know), so he hires Berkely Nunn (Peck) to find out if he's the author or not.

Along the way, the "Detective" scriptwriters throw in brassy dames, fisticuffs, coverups, studio politics and homosexuality - not to mention every cliche in the book. At times, it almost lurched into parody, but it was hard to tell.

And Peck is woefully miscast. His father, Cary, might have pulled this off, but even that's doubtful.

So, if you want to see a bit of Salt Lake City, tune in. If you want to see a decent television show, tune out.ELSEWHERE ON THE TUBE: Leonard Nimoy produced and starred in Never Forget (6 p.m. and 8 p.m., TNT), a fine, fact-based movie about an Auschwitz survivor who battles revisionist historians who claim the Holocaust never took place. If you've got cable, it's well worth watching or taping; Girls of Summer (8 p.m., Ch. 2) was called "Satisfaction" in the theaters, and the name change doesn't make this tale of an aspiring all-girl band any less a piece of garbage; the excellent miniseries Separate But Equal (8 p.m., Ch. 4); Murphy Brown (8 p.m., Ch. 5), much to her regret, agrees to appear as a guest on Corky's interview special; Julia must deal with the death of her boyfriend, Reese (real-life husband Hal Holbrook who's now on "Evening Shade"), on Designing Women (8:30 p.m., Ch. 5).

- LOOKING TOWARD TUESDAY: First Love, Fatal Love (7:15 a.m. and 9 p.m., HBO) is an excellent cautionary tale about AIDS; David Copperfield (7 p.m., Ch. 5) returns with another magic special; Shannon's Deal (9 p.m., Ch. 2) finally finds a spot on the NBC schedule; and Ellyn and Billy get married as thirtysomething (9 p.m., Ch. 4) returns to the air. - SDP