Conan O'Brien reveals the worst guest he's had in 25 years

Conan O'Brien revealed the worst guest he's had in his late-night career. (AP)

Conan O’Brien’s been hosting talk shows for 25 years and has interviewed thousands of celebrities. But he singled out one guest as the worst of all time.

On a recent episode of the "Armchair Expert With Dax Shepard" podcast, the TV host named and shamed American filmmaker Abel Ferrara as the worst celebrity he’s interviewed.

“Abel Ferrara was an eccentric director,” Conan said on the podcast.

“He fled during the show before his segment. He ran away, got on the elevator and was out on the street running away and Frank (the segment producer) gave chase and grabbed him.”

The producer managed to coax Ferrara back into the TV studio and pushed him on stage to be interviewed by Conan.

“He came on camera against his will and then came out and I think started yelling at me,” the talk show host recalled.

Ferrara, who made "Bad Lieutenant" (1992) and "The Funeral" (1996), slurred his way through the interview and appeared disinterested.

Able Ferrara previously appeared on 'Late Night with Conan O'Brien.' (Getty Images)

“Do you think he was intoxicated?” Shepard asked.

“Yes, I’m sure, or if not, he should have been,” Conan replied. “I remember it being entertaining. If you ate 15 cloves of garlic you wouldn’t say that was a great experience but you’d remember it.”

You can watch the trainwreck of an interview below:

Conan was less than impressed with another guest, who he hinted was a "Lost" star, who rocked up drunk.

“A cast member on a certain show where everybody’s trapped on an island’s had way too much to drink and comes out and you could smell it,” he said.

“They think they’re funnier, all they do is laugh at the things they say and the pauses they take are way too long, but in they’re mind they’re killing it.

“There are people who consistently come on and disrespect the form,” he said.

Conan said his pet hate is when actors come on and act as if they’re above appearing on a talk show.

“It’s just the tail wagging the dog — ‘If I’m difficult then I must be a genius.’ No, be a genius first and then if the side effect is you’re difficult, then we’ll accept it,” he said. “But don’t be difficult in the hopes that maybe you’re a genius.”

And finally, Conan praised actors from the UK who he said almost always make for good guests.

“I’m always blown away that guests from the UK; there’s something in the water,” he said. “They tell you a tale, they spin a yarn and it’s beautiful.”

This article originally appeared in news.com.au.