But a slew of "silly mistakes" followed, with Gillies turning down top roles because he believed he should stick with film.
"The last decade brought about startlingly good shows like The Sopranos, Breaking Bad, Lost, Game of Thrones. It's not even genre-specific. I didn't see television was becoming this burgeoning and respected animal, so I stuck to my guns and turned down great offers.
"I would run out of money and do a crappy movie I didn't want to do. I hurt myself because I could've sustained myself with incredible television."
Among his film projects was the 2007 horror flick Captivity, which became a real-life horror. Scripts kept changing, hours were gruelling and Gillies became increasingly-frustrated at the "spaghetti-like" mess of working under three directors. The film, co-starring Elisha Cuthbert, was dubbed one of the worst movies of 2007 and Gillies was distraught.
"I was in an American film playing a lead and it bombed. Years later, I can tell you it was my fault. But there's no young actor who would have turned down Roland Joffe, an Academy Award-nominated director.
"A film turning out shitty would destroy most actors but that's what I love about being a New Zealander. Kiwis create lemonade in the worst situations. I had to make the situation beautiful and the only way to do that was start from square one and make my own film.
"Captivity wasn't the greatest experience of my life, but I wasn't diagnosed with cancer ... as long as you're not dead you can keep fighting."
His resulting movie interweaves two stories - one following Gillies as a writer who forms a unique bond with a 14-year-old prostitute from the slums of Bogota, and the other centred on Cook (who also co-produced the film) as an LA teacher grappling with personal tragedy.
"I wanted to make a story about people," says Gillies. "I kept coming away from sets thinking, 'what the f*** is happening? Nobody's telling stories anymore.' Whenever I did a show or production in New Zealand, I always walked away from a director feeling like I learnt something. Here, I was walking away feeling like I wasn't even being directed anymore."
Thinking it would take 18 months, Gillies grew a beard, "a talisman of my own stubbornness", vowing he wouldn't shave until the film was completed.
It would be three years before Rachael, 33, got her clean-shaven husband back and in that time he learned Spanish while living on and off in Colombia, sleeping on floors in Berlin while chasing recession-hit investors and raising, then losing financers so many times that he stopped counting - and is still too pained to think about.
He refused an offer of US$100,000 ($121,000) from his in-laws and gradually his own bank account, fuelled by films like Spider-Man 2, drained.
"I don't know if I was clinically-depressed but I was certainly unhappy for long periods," admits Gillies. "But that's life. If the whole thing was a joy, I wouldn't do it. There would be no obstacle. I remember Bob Dylan once saying, 'What's happy? Anybody can be happy.'
"I don't agree entirely because I think there's a degree of wisdom and simplicity in being happy. My wife, for example, is very wise, deeply-intelligent and makes a priority out of being happy, but I feel like some of us ... we're restless. We'd rather compromise our happiness in order to be exactly who we are.
"I also believe some people are born with a blueprint to make shit happen and I'm probably one of those people. Not to sound self-aggrandising and, hey, only 12 people might watch the next 10 films I make, but I am definitely someone who says he's going to do something then carries that out ... hell or high water."
The hell part of that journey saw Cook - best-known for her role in the 1999 romantic comedy She's All That and more recently in TV series Psych and Perception - start to wonder "how long this would be our life", while the emotional toll on Gillies culminated in a panic attack while driving to the dog park in LA.
Cook found him sitting kerbside, head-in-hands, before he was taken to hospital.
Unable to quit, but desperate for funds, Gillies took one of the hardest steps of his life - accepting the $100,000 from Cook's parents to kick-start production.
His unstoppable mission had, meanwhile, became so fascinating to those around him that they filmed a documentary about the making of the movie, titled Kingdom Come, and also featuring commentary from fellow indie film-makers like Selma Blair and Don Cheadle.
Broken Kingdom won Best Director and Best Feature Film at the Rhode Island International Film Festival and Outstanding Achievement in Film-making at the Newport Beach Film Festival. It was finally released online brokenkingdom.com for NZ$6 in October - Gillies all but giving the film away for free because all he wanted was for the film to be widely viewed.
Yet with the high of wrapping production - a day he marked by getting a tattoo - came the sinking realisation that he was more than $100,000 in debt and had been out of the Hollywood game too long.
Asking his agent to submit him for everything, a string of TV stints followed, including True Blood with fellow Kiwi Anna Paquin, NCIS and medical drama Saving Hope.
But it's his role as Elijah on TV2's cult hit The Vampire Diaries that has earned him major success, even if it is with the teen set. Show creator Kevin Williamson says he got lucky with the "terrific, phenomenal actor" while co-creator Julie Plec says, "There is no joy in this world if Daniel Gillies is ever killed off for good!"
It's not just his bosses Gillies has won over. Asked which of their castmates they want to see their character hook up with during a recent convention, there was a resounding "Elijah" among the show's leading actors - both male and female.
"Maybe they've taken pity on me because I'm not as attractive as them," he ponders. "I have no idea why they're speaking so fondly of me."
Humble he may be, but there's no denying the epic following the series has garnered internationally. Gillies is still getting accustomed to teenage adoration - and reluctant male recognition.
"My wife and I were in Bangkok and there's this conservative but adorable aspect of Thai people. They'd casually say, 'I know you're an actor but I don't watch it.'
"Then we'd go for drinks and through the course of the night it became, 'I f****** love Elijah! I've seen every episode!'
"I didn't realise how globally-popular the show was. I've never been part of anything like this. But when you have young men in cool clothing, pouting, beautifully-lit and talking about how much they love one girl, with a danger and sweeping romance thrown in, it's a bullet-proof marketing strategy."
The hypocrisy of stepping away from the "lost of art of directing" in Hollywood, then returning to recover his finances isn't lost on Gillies.
And though he still notices the same shortcomings, he says experiencing the "monumental responsibility" of directing Broken Kingdom, has made him calmer and more empathetic towards directors on US sets. He's glad to have finally paid back his in-laws and rescue his own finances, following the tornado of debt Broken Kingdom left behind.
It was Cook who supported the pair during the final months of shooting the film. Cook and Gillies, who have been married eight years, originally met in a bar.
"I was too proud to take the support but she justified it by saying, 'Honey, if you were in medical school I would be supporting you, and you'd be supporting me if I was in school.
You're in the best film school of all time - you're making a film.'
"It was incredibly gracious and sweet and I'm grateful we didn't have kids early because that's the luxury you have when you don't have children - being able to do extraordinarily risky business ventures. I'm not sure I would have taken that risk as a father."
Though he's now working on two further independent movies, it's fatherhood that Gillies is looking forward to next. As one of four children, now scattered from Australia to Germany, he's excited about the prospect of starting his own family.
He and Cook likely won't be raising them here, however - while he misses New Zealand, the couple has no plans to relocate. "This [LA] is home now. I miss the simplicity of New Zealand - and not having traffic - but would I ever go back? No. I love it here. Maybe it's the weather.
"People ask if it has grown on me over time, but I drove into LA and loved it right away.
"Rachael loves New Zealand. She's like, 'this is so abundant, fresh, beautiful and small'.
I'm more nostalgic. I have so much history and often feel like I'm looking through a misty piece of glass.
"I think New Zealand is one of those places you grow fonder of the more time that goes by that you're away from it."
The Vampire Diaries returns to TV2 on February 14.
