Nasty, surly, bitchy, smarmy, loutish, imperious, vain, vicious, loathsome, arrogant, smug, snide, obnoxious, rude and mean. Those are only some of the adjectives that have been applied to Simon Cowell during his reign as executioner on American Idol, which on January 16 begins its sixth season on Fox.

Cowell, 47, is the grandest prime-time villain since J.R. Ewing, overshadowing fellow Idol judges Randy Jackson and Paula Abdul and host Ryan Seacrest. With a lordly flair and a stagy British accent, he dismisses aspiring singers with a roll of his eyes or a lash of his tongue.He started his career in the mail room at EMI; his father, Eric, a prosperous executive, ran the company's property division. But the younger Cowell struggled in the music business and even went bankrupt. At the age of 30 he returned home to live with his father and mother, Julie, who remains very close to her son. Cowell made his breakthrough by signing a deal with Robson & Jerome, a pair of British actors who had sung the Righteous Brothers hit "Unchained Melody" on a TV show but weren't interested in recording. Cowell persisted, telephoning the pair repeatedly, and their record became the top-selling British single of 1995.Soon he had cornered the market in shamelessness and attained a lucrative position releasing novelty records; he signed the Mighty Morphin Power Rangers and the World Wrestling Federation, including its most gruesome wrestler, the Undertaker. Most of his acts, including Curiosity Killed the Cat, 5ive and Sinitta, had only flashy, fleeting success, though he also signed Westlife, an Irish boy band that now has more U.K. number one hits than anyone except Elvis Presley and the Beatles.American Idol debuted inauspiciously in June 2002 as a summer replacement series on Fox, after the program had been rejected by ABC, NBC, CBS, the WB and UPN. The show was based on Pop Idol, which had premiered on TV in the U.K. the previous October. It was devised by Cowell--the only judge to appear on both programs--and Simon Fuller, a Brit who had managed the Spice Girls. By the time season one ended, with Kelly Clarkson's victory, American Idol had an audience of more than 26 million viewers.The division of riches seemed tidy: Cowell released Idol-related records on his Sony BMG-distributed label, while Fuller owned part of the show and managed the Idol winners' careers. But in 2004 the two partners ended up in a legal battle after Cowell produced a new U.K. talent competition, The X Factor, and Fuller accused him of stealing the idea from Pop Idol. The lawsuit was settled, with Cowell agreeing to return to Idol for five more seasons. Recently he has become a reality-TV magnate, producing three other shows (American Inventor, America's Got Talent and Celebrity Duets), with as many as 10 more programs going into production.Playboy Contributing Editor Rob Tannenbaum spent two afternoons with Cowell in his London office. "Simon's mouth is always in motion," he reports. "One minute he's eating fruit, drinking tea or taking drops to combat migraines. The next he's giving instructions to his assistant--whom he addresses as 'sweetheart,' as he does most women--or he's on the phone, giving typically strong opinions: 'It's stupid, stupid, stupid. It's just pathetic, in fact.'

"He's too cheeky and mischievous to really be a tyrant, but it doesn't look fun to be on the receiving end of a Cowell insult. He told me he gets ornery only when bored, so I did my best not to bore him."

Playboy: Let's get to the heart of the matter. Are you, Simon, an asshole?

Simon Cowell: [Laughs] Well, I don't think I am. But based on public opinion, yeah, I am. If half the people think I'm an asshole, then I'm half an asshole.

Playboy: What does the other half think?

Cowell: People say, "I like your honesty," or "I like the fact that you're not politically correct." To be truthful, I don't think I'm an asshole. To me, an asshole is someone who pretends to be nice in public but is a complete monster behind the scenes.

Playboy: So you're no more of a monster in private than you are in public.

Cowell: Funny enough, I'm quite polite in real life. I don't tolerate rudeness to people like waiters or stewardesses.

Playboy: You certainly don't seem polite on American Idol.

Cowell: Well, if I tape an 11-hour day, guess which 20 minutes end up on the air. Not the bits when I'm pleasant but the parts when I'm obnoxious.

Playboy: When people see you in public, are they rude to you?

Cowell: Normally they want me to be rude to them. People come up to me and sing, and I say, "That was great. Thank you." And they're like, "Well, aren't you going to be rude to me?" No. "Well, can you be rude to me?" No! When I miss auditions, contestants get upset that I'm not there, because they expect me to be cruel to them--it's some sort of badge of honor. That's how crazy everything is.

Playboy: Maybe later we'll sing for you, and you can tell us what you think.

Cowell: You really want to do that? You don't really want to do that.

Playboy: Why not?

Cowell: Because I've spent so much of my life sitting in talent meetings, thinking, What the hell am I going to say at the end of this? You know, about 15 years ago I was going to work with Eddie Murphy. He was interested in making a record, so I flew to the East Coast, to his huge house, and I was very intimidated. I thought it would be just the two of us and a hi-fi. But I ended up in a recording studio with about 20 nodders; a nodder is somebody who gets paid to agree with the person paying him.Eddie started to play some songs, which I hated, and I just didn't know what to say. Now I'd find it a lot easier. I would just say, "I hate it."