GRAHAM Norton has a long memory. Like Santa, he knows exactly who has been naughty and nice.
Considering the long list of famous bottoms that have sat on his red couch, it takes a standout performance to be named the chat show host's best or worst guest.
After a long wait to secure his first interview with Tom Cruise, Norton says the Top Gun star quickly became one of his favourites.
Though he is known as something of a loose cannon - Cruise famously jumped on Oprah's couch while declaring his love for then-partner, Katie Holmes - it's his behaviour behind the scenes that most impresses.
"Someone like Tom Cruise is incredible," Norton says.
"He comes in and gets introduced to everyone, as happens with every guest, and he remembers everyone's name. And on the way out he remembers everyone's name and what they do. Clearly, that is some sort of mental trick, but it's a very impressive one, and clearly the rest of us aren't bothered learning it, so that means people backstage love him."
Now a repeat visitor to the show, Cruise has had a dance party with Zac Efron, encouraged comedian Catherine Tate to get sweary, and shared impressive stories of stunts gone wrong, such as throwing up in a fighter jet.
Other big names who make Norton's ''nice list'' include Will Smith and Tom Hanks. He says the best guests bring "star voltage" with them - but never forget where they came from.
"The audience and I don't get over the fact that that person is now flesh and blood and in the same room as us," Norton says.
"It sounds ridiculous, because it's such an ephemeral, unspecifiable thing, and yet it's true. And someone like Tom Hanks can really tell a story and will talk about all of his career ... even Turner & Hooch."
Norton is understandably reluctant to name and shame his least favourite guests - it's bad form to gripe publicly, it turns off prospective guests - but there is one who left him feeling thoroughly exasperated.
"Someone like Mickey Rourke, he was just exhausting because he wanted to smoke all the time," Norton says.
"I'd turn away for a second, turn back, and he'd have lit another cigarette. It was so boring. You feel like a teacher taking children on a school trip, not a chat show host."
Wrangling celebrities is fraught with difficulty, so Norton has strategies in place for those who don't play nicely.
"On the night, once you realise 'You're awful!' about a guest, you just try to shut them up and focus on the other guests," he says.
"The audience hated one guest last season. The person was difficult and kept dropping weird words into the conversation as if they had a bet with someone. I just talked to the other guests, and their bit got edited right down in the end."
Another behaviour he doesn't appreciate is "snippiness", though what you see isn't always what you get.
"There have been a few people who've been a bit snippy. Mostly, though, famous people employ snippy people to save them having to be like that. Sometimes I'll meet the star and they'll even apologise for their people's behaviour, and I'm thinking, 'Yeah, but you chose to surround yourself with these people and that says a lot about you'."
There are huge names in store for the show's 22nd season, currently airing on Channel 10.
The woman who would've been President, Hillary Clinton, drops by on October 27.
Nicole Kidman, whose career continues to hit new heights is on the list, and we've already seen Aussie actor Margot Robbie tattoo an audience member - badly - when Norton revealed the Aussie star likes to dabble with ink. Showing she's no slacker in the star stakes, Robbie wowed the crowd, no mean feat while sharing a couch with A-listers Reese Witherspoon, Ryan Gosling and Harrison Ford.
Having reigned as a chat show host, with wine in hand, since 2007, Norton has TV down to a fine art. In recent years, he has explored his abilities as a writer, first with autobiographies, and more recently his first novel, Holding. As you might expect from such a prolific entertainer, he has found considerable success. Holding was a bestseller and won The Irish independent Popular Fiction Book of the Year award … not bad for a debut novel.
"It's possible that Norton has been wasted on TV all these years," declared the Irish Times.
Norton, who has lived in London for many years, says that achieving critical success in his native Ireland was important to him. "I was absolutely thrilled with the reception Holding got, because you have no idea how you'll do.
"I was particularly gratified that the book did so well in Ireland because it was set in Ireland, and I was worried about how people would react to me writing a book set there because I haven't lived there full time for so many years. It was really pleasing.
"It's not a crime book; it's set now and in 1973 and has two interconnected stories. It's set in the rural Ireland I know very well - when you sit down with a laptop to disappear into those villages and that scenery, it's a very nice place to go."
The Graham Norton Show, Friday, 8.30pm, Channel 10
Update your news preferences and get the latest news delivered to your inbox.