Since its debut, Mad Men has had a lock on the Emmys’ marquee drama series category. Last year, it fended off a formidable challenge from another period drama, HBO’s Boardwalk Empire, which was coming off a best drama series at the Golden Globes. In doing that, Mad Men matched The West Wing and Hill Street Blues’ record four consecutive Emmys in the top drama category.

Mad Men’s quest to become the first drama series ever to win five years in a row is becoming even more difficult this year with several hot series gunning for the prize. Showtime’s acclaimed Homeland has been on a roll, winning for best drama series at the Golden Globes, PBS’ pop culture phenom Downton Abbey is entering the drama series fray after winning the Miniseries or Made for Television Movie category last year, and AMC’s Breaking Bad is back at its best after skipping last year’s Emmys because of a long hiatus between seasons. Add to that a surging Game Of Thrones and still potent Boardwalk Empire, and we get a very competitive best drama series Emmy race this year. Here’s our assessment of the chances for drama series (in alphabetical order) and their stars:

Boardwalk Empire
Although HBO’s Prohibition-era Mob drama was received warmly enough in its first season to earn it a nomination, it really hit its stride in its second season. So, not only is it certain to be given another nod, but so are prior nominees Steve Buscemi (lead actor) and Kelly Macdonald (supporting actress). Furthermore, since it was the dazzling downward spiral (and eventual murder) of Michael Pitt’s Jimmy Darmody that proved to be the shot in the arm that the show needed, maybe this year he won’t be left out of the supporting actor race.

Kelsey Grammer’s new political drama delivered underwhelming ratings for Starz, which had renewed it before the premiere. However, Boss landed Golden Globe nominations for drama series and lead actor, and won for the latter. Its leading man is such an Emmy mainstay — the erstwhile Frasier Crane has won five statuettes over the course of his small-screen career — that it would be a mistake to count him out.

Breaking Bad
This intense drama is a top contender to steal away the drama series Emmy from Mad Men. After a long hiatus kept AMC’s other prestige drama out of the running in 2011, Breaking Bad returned with its strongest season to date. In its wake, nods are all but guaranteed for co-stars Bryan Cranston (who took home the lead actor prize three years in a row) and Aaron Paul (who won supporting actor the last time he was eligible). Plus, thanks to the year’s most talked-about swan song (and one riveting performance after another before it), Giancarlo Esposito is also looking good for a supporting actor in a drama series nomination.

Since the legal thriller’s penultimate season, its first on DirecTV, flew so far under the radar that it scarcely generated a blip, it’s a bit of a long shot for a drama series nod. Its stars, however, are another story. Glenn Close has been up for lead actress every year since the show’s debut except the last (and took home the prize in 2008 and 2009). (She also won in 1995 for the NBC movie Serving In Silence: The Margarethe Cammermeyer Story.) Meanwhile, two-time supporting actress contender Rose Byrne is likely to benefit from the raised profile that she has enjoyed post-Bridesmaids.

In spite of its long and illustrious Emmy history, Showtime’s killer serial is facing a daunting uphill battle this time around. Thanks to villains who paled in comparison to their predecessors, played by Emmy winner John Lithgow and nominee Jimmy Smits — and an unpopular plot hinting at a possible a romance between sorta-siblings Dexter and Deb — the show (and its star, Michael C. Hall) could be left on the sidelines for the first time since 2007.

Downton Abbey
Having emerged victorious in the miniseries or made for television movie category in 2011, PBS’ pop-culture phenomenon is gambling by putting itself in the running for drama series: Its second season was regarded with a good bit less enthusiasm than its first. However, the buzz surrounding its switch of categories should increase its visibility and, with that, its chances. And, if Hugh Bonneville and Elizabeth McGovern aren’t surefire nominations for lead actor and actress, respectively, at the very least last year’s winner for supporting actress in miniseries or made for television movie — Maggie Smith — is guaranteed another nod (this time, obviously, for supporting actress in a drama series). The wildcard: a supporting actress nom for Lady Mary: the luminous Michelle Dockery.

Game Of Thrones
Since HBO’s medieval fantasy got better — and grew more popular — as its wars got underway in its second season, a repeat drama series nomination is the safest of bets. The same goes for Peter Dinklage, last year’s winner for supporting actor. If another member of the cast of thousands manages to break into the races, look for it to be the formidable Emilia Clarke or Lena Headey who’ve been submitted for the best supporting actress slot.

The Good Wife
The drama remains CBS and broadcast TV’s best — and likely only — chance at a drama series nomination. It’s also a given that last year’s lead actress winner, Julianna Margulies, will get another nod, so will many of the supporting players, and the show’s all-star guest cast will rack up enough nominations to fill those categories all by themselves. (That isn’t an exaggeration.) In jeopardy: a nod for Archie Panjabi. She was named supporting actress the first time she was nominated (in 2010), and was in the running again the following year. But, this season, she may have spent too much time on the back burner to generate the heat she’ll need to stay in the race.

Homeland Damian Lewis and Claire DanesShowtime’s new breakout hit is riding such an enviable wave of acclaim that it is arguably the only series other than Breaking Bad that has a real shot at ending Mad Men’s reign. (Even President Barack Obama has admitted he’s crazy about it!) In any case, the show is at least a lock for a nomination, as are Damian Lewis (for lead actor) and Claire Danes (for lead actress). In fact, the previous Emmy winner (for the 2010 HBO movie Temple Grandin) just might be the one to beat.

Since Fox’s long-running medical drama is coming to an end, sentimental Emmy is sure to want to acknowledge it one last time. But, rather than nominate the show itself (it’s been denied a drama series nod for the past two years), voters will probably be more inclined to give Hugh Laurie a final — and his seventh! — chance at lead actor. Maybe this time, he’ll even win.

Creatively, FX’s modern Western remained in great shape. However, as stellar an actor as Neal McDonough is, his Robert Quarles was a far less showy villain than his predecessor, Emmy® winner Margo Martindale’s Mags Bennett, making the show, as ever, a long-shot for a nomination. Instead, bank on Timothy Olyphant to compete again for lead actor and Walton Goggins, a nominee for supporting actor last year, to edge McDonough out of that race.

Promising as it was, HBO’s cancelled racetrack drama stumbled out of the gate, delivering low ratings and bad press. So, in spite of its impressive pedigree — its creator is four-time Emmy winner David Milch (NYPD Blue); its executive producer, two-time victor Michael Mann; its star, Oscar winner Dustin Hoffman — in this derby, it’s a dark horse.

Mad Men
Obviously, having won four times in a row for drama series, the show will be nominated again — that’s as certain as Don Draper going through a pack of cigarettes over the course of any given episode. Previous contenders Jon Hamm and Elisabeth Moss are also shoo-ins (for lead actor and actress, respectively). The question is: will the AMC juggernaut be able to win again? By well past mid-season, it had yet to yield an episode of the nosebleed-high caliber of its wildly (and rightly) praised “The Suitcase.” If it doesn’t get an “it” episode out before voters begin to cast their ballots, that could leave the race open to an upset by the superlative Breaking Bad or Homeland. Meanwhile, although January Jones — previously nominated for lead actress — has returned to the supporting actress category, her real-life pregnancy kept her off screen for so long that she’s unlikely to make the cut. Instead, that slot will be filled by two-time nominee Christina Hendricks.

Once Upon A Time
Once Upon A TimeTo overcome Emmy’s bias against genre series, ABC’s freshman fairy tale will likely need more magic than even its strong ratings can conjure up. Worthy as the performances of Jennifer Morrison and Ginnifer Goodwin are, the show’s best chance to be recognized in a major category is probably a supporting actor nod for Rumplestiltskin’s nimble portrayer, Robert Carlyle, a 2006 contender for his work in the Lifetime movie Human Trafficking.

Since historically the Emmys® haven’t taken soap operas seriously — Dallas was only nominated for drama series twice in its 1978-91 run! and recent best series Emmy nominee Desperate Housewives has competed as a comedy — ABC’s Hamptons-set grudge match should be braced for a snubbing. Basking in glowing reviews, the show’s resident ice queen, Madeleine Stowe, should be a safe bet for a nomination — but she’s going head-to-head with the series’ ostensible star, Emily VanCamp, for the lead actress slot. One of them might have gotten the nod, but both? Not a chance.

While awareness of Showtime’s dysfunctional-family affair grew in its second season, it remains as much of an underdog in the Emmy® races as its low-class clan is in life. If series leads William H. Macy and Emmy Rossum are nominated, it will be, however well-deserved, a miracle.

After The Good Wife, NBC’s musical drama is probably the strongest broadcast contender for the series category, though its chances might be affected by the recent behind-the-scenes change with creator/showrunner Theresa Rebeck being replaced by Gossip Girl EP Joshua Safran. Smash’s Emmy hopes largely rest on the shoulders of lead actress contender Debra Messing, a six-time nominee and 2003 winner (for Will & Grace), and Megan Hilty, a buzzed-about wildcard in the supporting actress race.

Sons Of Anarchy
Were it not for the number of strong new shows vying to break into the drama series category this year, FX’s biker series might have been able to sneak into the race, finally: Its fourth season was that solid. Unfortunately for the show, as well as for standout cast members Charlie Hunnam and especially Maggie Siff (the Mad Men alumna who got better and better, the worse things got for her character, Tara Knowles), the best chance of a nod is for series’ female lead Katey Sagal who is seeking her first Emmy® nomination.

A modest hit greeted with lukewarm reviews, Fox’s freshman drama might be a total Emmy write-off, were it not for its star. With seven lead actor nominations under his belt for 24 (as well as a win in 2006), Kiefer Sutherland stands a decent — and the show’s best — chance of eking out a nod.

The Walking Dead
Given Emmy’s longstanding bias against genre shows (see also: Buffy The Vampire Slayer and Fringe) and the fact that AMC’s monster hit wasn’t nominated last year, when its freshman season generated such deafening buzz, it’s highly unlikely that it will get a nod this year. That’s also probably bad news for its would-be nominees, unsung hero Andrew Lincoln, who belongs in the lead actor race, and Jon Bernthal, who made his character’s descent into madness as terrifying as any zombie attack.

Blue Bloods (CBS)
The Closer (TNT)
Fringe (Fox)
The Killing (AMC)
Parenthood (NBC)
Rescue Me (FX)
Scandal (ABC)
Southland (TNT)
Spartacus: Vengeance (Starz)
Suits (USA)
True Blood (HBO)
White Collar (USA)

(’s Andy Patrick contributed to this analysis.)