American Idol 8 p.m., Fox

The 15-season series ends on Thursday night. That’s an occasion to look back on the best of Simon Cowell, the judge who gave the series its initial — hmm, what’s the right word? — vigor.

Cowell was the voice of reason, the bad dad, the lewd dude, the cranky pants, the dogged realist. Here are some of his best lines, which you can only recite with a British accent.

Clearly, the guy wasn’t there to make friends.

“Did you really believe you could become the American Idol? Well, then, you’re deaf.’’

“You sound like a cat in a vacuum cleaner. Dreadful.’’

“If you would be singing like this 2,000 years ago, people would have stoned you.’’

“You sing like a 3-year-old girl dressed like LaToya Jackson.’’

“You look like the Incredible Hulk’s wife.’’

“You sounded like Dolly Parton on helium.’’

“It was almost like you were giving birth there at the end.’’

“You actually sing like a train going off the rails. You sort of start off in tune and then it goes completely off. And very, very fast.’’

“You sounded like Cher after she’s been to the dentist.’’

“That song was like going to a zoo or something. I mean the noises were beyond anything I have ever, ever heard.’’

“You have the personality of a handle.’’

“Last year I described someone as being the worst singer in America. I think you’re possibly the worst singer in the world.’’

Matthew Gilbert can be reached at gilbert@globe.com. Follow him on Twitter @MatthewGilbert.