In his typical deadpan manner, British comedian Ricky Gervais says the series finale of his HBO series

Extras

(tonight at 9)

is the best work he's ever done. And then he pauses. So you wait. For the quip. For the zinger.

Because it's Ricky Gervais speaking. The man who's rocketed to stardom by mocking celebrity pomposity. The guy who dreamed up, wrote and starred in the original British version of

The Office

and helped create the American knockoff. The ridiculously prolific funnyman who not only wrote and played in two seasons of

Extras

, but has also authored a children's book (

Flanimals

), hosted a short series of interview shows in England, appeared in a couple of Hollywood movies, developed a wildly popular podcast (3 million downloads), and toured both sides of the Atlantic with a live stand-up routine poking fun at fame.

But he's not joking.

Not about this particular

Extras

episode, which is a Christmas special crammed with bizarre star cameos from the likes of Clive Owen and George Michael, as well as a graceful swan song. This, he says in all seriousness, is the best thing he's ever written.

In its brief television life (six episodes in the first season, six in the second, and now the 90-minute finale)

Extras

garnered enough comedy clout to be favorably compared to Larry David's

Curb Your Enthusiasm

and

Monty Python's Flying Circus

. It regularly featured A-list guest stars such as Kate Winslet, Orlando Bloom, David Bowie and Robert De Niro. And at this year's Emmys, Gervais (jer-VASE) walked away with the award for best actor in a comedy for his portrayal of Andy Millman, the program's anti-leading man who is forced to suffer the indignities of showbiz's fringes and is prone to saying the wrong things, at the wrong time, to the wrong bigwigs.

"The point of

Extras

wasn't just about integrity versus celebrity. It was to show that friendship is the most important thing in the world. This episode is a bit sadder than most others, and I wanted it to be," Gervais says.

At the beginning of

Extras

' second season, viewers watched Andy rise from lowly movie extra to sitcom star, while his best friend Maggie (played by Ashley Jensen, who also plays Christina on

Ugly Betty

) saw her own career (literally) go in the toilet.

The problem was that Andy's hit BBC show,

When the Whistle Blows

, was an insipid Britcom complete with bad wigs, bad teeth and constant, crude double entendres. Andy was reduced to repeating his character's catchphrase, "Are you having a laugh?", like a broken record. He hated the gig. He hated that he'd become a sellout. But he loved the perks of being a celebrity.

In the series finale, Andy finally decides he's had enough and quits.

Convinced that his newfound celebrity will pave the way to substantial film offers, Andy fires his agent Darren (played by Gervais' real-life writing partner Stephen Merchant) and distances himself from Maggie. He tells stunned BBC executives that he expects his "phone won't stop ringing."

Famous last words. Now Andy has to decide just how low he's willing to stoop to revive his celebrity profile. Are there more demeaning acting jobs than playing an alien slug on

Doctor Who

? You bet there are.

"I wanted to just go straight for the jugular," Gervais says, explaining that while he stayed true to his now-familiar brand of embarrassment comedy, he deliberately wove a thread of pathos into this seasonal special. And, he adds, it wasn't easy.

"People think doing stand-up is the holy grail, but it's so much easier to get good at that than it is to get good at writing a sitcom," he says. "With stand-up you can do a routine 100 times, and if they don't laugh at a bit, you can take it out. But with a sitcom you can't second-guess.

"I was absolutely meticulous about the writing of this because there are so many possible pitfalls when you're transferring what you think is funny in your mind to what is funny on screen."

Gervais says he wanted

Extras

- a series about shallowness and insincerity - to end on a resoundingly honest note because it will be his last creative statement about fame.

"I know, it's quite an explicit theme in everything I do," he says. "But this is going to be the end of it. It's time to focus on other things."

Raised in working-class Reading, England, as the youngest of four siblings, Gervais, 46, says he never intended to become a comedian. He entered University College in London to study biology, but switched to philosophy because the courses were easier. In the '80s he was a singer in a less-than-successful glam-rock band called Seona Dancing, sporting a sexually ambigious look complete with highly arched eyebrows and blue eye shadow.

Gervais worked as a disc jockey for a while, and played a bit role as an ignorant reporter on a British television program called

The 11 O'clock Show

, which also featured Ali G. It wasn't until Gervais was in his mid-30s that he teamed up with his longtime friend and writing partner, Merchant, to develop

The Office

, and was subsequently catapulted to fame as workplace horror David Brent.

Now, Gervais is turning his attention to writing and acting in films, and says he'll continue to collaborate with Merchant and Karl Pilkington to make more audio and video podcasts.

He's currently residing in New York while shooting a romantic comedy written and directed by David Koepp called

Ghost Town

, costarring Tea Leoni and Greg Kinnear. In it, Gervais plays a character he calls "a misanthropic loner" who dies while undergoing a colonoscopy and is revived. When he comes back to life, he realizes he can see the dead. But, Gervais says, "he doesn't like dead people either."

Ah, the proverbial lose-lose situation. Right up Ricky's alley.