This could be the year that HBO conquers its final Emmy frontier.

The pay cabler pretty much basks in unlimited TV Academy love these days, but one prize has so far eluded the 800-pound kudos gorilla: the outstanding drama series Emmy. The shutout remains despite heavy nomination loads in recent years for HBO staples “The Sopranos” and “Six Feet Under.”

“Sopranos” leads James Gandolfini and Edie Falco have both won acting trophies, and the show has been recognized for its writing, among other honors.

“Sopranos” has competed three times in the drama category; “Six Feet Under” competed for the top prize last year, among its staggering 23 noms. But neither has brought home the Big One for HBO.

“Between these two, the fact that they’re such landmark, groundbreaking shows, and everybody wants to be like them, this would be the year,” says TV Guide critic Matt Roush.

In a bit of irony, Robert Greenblatt, exec producer on “Six Feet Under” and the newly crowned programming topper at Showtime, is eager to lead the HBO charge.

“We’re gonna bury the ‘Sopranos,’ ” Greenblatt jokes. “Seriously, it’s a tough category. I’m thrilled to be in that company. If their show were to win, it would obviously be disappointing for us.

“Last year, we had the most nominations and everyone said we were the favorites including Aaron Sorkin (‘The West Wing’) and then he won. So who knows?”

Theories abound why HBO can’t seem to score that top drama prize. Perhaps many Academy of Television Arts & Sciences voters remain unconvinced that a cable series deserves the top trophy. Or perhaps “Sopranos'” gritty content has scared some Academy members away.

Others argue that, despite all the attention surrounding HBO’s programs, the pay cabler is still seen in a fraction of the homes that the broadcast nets reach.

Still, most of those concerns were thrown out the window in 2001, when HBO’s “Sex and the City” won the comedy series Emmy. “Sex” remains the only nonbroadcast show to win a best comedy or drama kudo.

But this time out, HBO has two shots at the top drama trophy, with “Sopranos” and “Six Feet Under” in the running together for the first time. The former returns after last year’s eligibility hiatus, while the latter leads the nomination tally for a second straight year (with 16).

The momentum appears to be on HBO’s side. Overall, the channel has amassed an unprecedented 109 noms, the most mentions for any broadcast or cable outlet since the ATAS allowed cablers to start competing 15 years ago.

“The truth is we always look at nominations as a real indication of how our programming is being received by our peers,” says HBO chairman-CEO Chris Albrecht. “It’s incredible to get this kind of validation for such a broad cross-section of our stuff.”

“You get the sense looking at the nominations, it seems like the industry only watches HBO or has a huge appreciation of what they do,” Roush says. “It seems like this would be the year that they would hit that landmark. Since they dominate in the nominations, I wonder what the voters are waiting for.”

“Sopranos” and “Six Feet Under” will face some pretty formidable competition: NBC’s three-peat drama victor “The West Wing” as well as Fox’s up-and-coming “24” and CBS ratings titan “CSI: Crime Scene Investigation.”

“I think it’s anybody’s trophy,” says David Janollari, an exec producer on “Six Feet Under.” “All I know is last year far too many people said to me and my partners on the show, ‘Oh, you’re so going to win.’ Obviously, that wasn’t the case.”

Many believe “Sopranos” is the front-runner this year, given that the revolutionary show — which forced programmers of all types to completely reassess how they develop series — has not yet won the award.

There’s probably also a pent-up desire to recognize the skein, which was out of the running last year due to a lengthy hiatus. And even content issues seem to have fallen by the wayside, as much of TV has caught up to the show’s edgy content (“The Shield,” “Kingpin”), making “Sopranos” much more palatable to mainstream auds than when it was launched.

“Just judging on the high points of the season, ‘The Sopranos’ had high points that exceeded what everyone else did,” Roush says. “This show really defined HBO and what drama could be. It led the way to the things FX is doing, and the impact and influence ‘The Sopranos’ has had on the industry speaks for itself.”

On the flip side, “Six Feet Under” has obviously struck a chord, having even topped “Sopranos” in noms. The show also may be a touch more easy for Emmy voters (particularly older Academy members) to digest.

“When you look at our show, I felt this was just as good, if not the best season,” Janollari says. “The critics couldn’t have been more in love with the show. Of course, this is not a critics award, it’s a TV Academy award.”

Producers wonder, however, if “The Sopranos” and “Six Feet Under” will cancel out the HBO vote, leaving a hole open for one of the remaining nominees (most likely “24”).

“I don’t know that answer, but it’s certainly a question that makes sense,” Janollari says. “The fans of our show are also fans of ‘The Sopranos’ for the most part. One of the reasons we wanted to do the show at HBO in the first place was because of ‘The Sopranos.'”

But while critics and producers say the drama Emmy category is a jump ball, most believe “Sopranos” and “Six Feet Under” at the very least won’t have to worry about “West Wing.” Not only has the Peacock program won three drama Emmys, but this season was considered a creative low point.

“It will be a big shocker if ‘The West Wing’ wins for a fourth consecutive year,” Roush says.