Wednesday marks David Letterman’s final show — at least until he returns two years from now as a member of “The View.”

One of the talk show host’s attributes that has been most celebrated in recent weeks is his realness. He doesn’t suffer fools, and when he dislikes a guest, the audience knows it. You won’t find him convulsing with pretend laughter during a lame anecdote by the third lead on an NBC sitcom, a la Jimmy Fallon.

No, Letterman is wonderfully crusty — and we wouldn’t have him any other way

In celebration of Letterman’s final curtain call, here are five times it was pretty clear he could barely tolerate the person sitting in the chair next to him.

Paris Hilton

He begins the 2007 segment by introducing the socialite as “a woman of many talents,” sarcasm creeping into his voice. Then when the interview finally gets going, he questions Hilton about her recent stint in prison for driving with an expired license — much to Hilton’s obvious embarrassment.

As the interview drags on, Letterman continues to twist the knife, asking more and more ridiculous questions as Hilton reverts to three-word answers.

“Have your friends treated you differently now that you’re out of the slammer?” he asks at one point.

When Hilton finally breaks and angrily tells him she’s not going to talk about her prison stint anymore, the host replies, “This is where you and I are different. This is all I want to talk about.” Wonderful.

Donald Trump

During a 2012 appearance, Letterman allows the real estate mogul to bloviate about how China is overtaking the US. When Trump begins plugging his clothing line, Dave casually asks, “Where are these made?” Turns out in China.

“In all fairness, I’ve been very open about that,” a chastened Trump responds.

Trumped!

Richard Simmons

The workout guru was a frequent guest on Letterman’s show, and Dave always took great pleasure in taking mean swipes at the sensitive Simmons.

During this 1994 appearance, Letterman pranks Simmons by telling him his idol, Barbra Streisand, is backstage. Simmons nearly collapses. Finally, Letterman introduces Streisand, but instead, Larry “Bud” Melman walks out and sings “Memories.”

“No one’s ever been this cruel to me ever,” Simmons says, obviously hurt.

In 2012, Simmons told US Weekly of Letterman, “You know, I’ve never actually met him? You do the show with him, and when they go to commercial, they remove you. You’re just not allowed to talk to him. Or if you are, he’s very standoffish.”

“The last time I was on, we went to commercial and I was like, ‘I’d love to meet your wife!’ He was like, ‘You never will.’ And then I was like, ‘And see your son!’ And he was like, ‘You’ll never see him.’ And then we come back from the commercial and he’s all friendly with me again.”

Harmony Korine

When the indie filmmaker arrives in the chair beside Dave in 1998 wearing a hoodie and T-shirt, Letterman says, “Thanks for fixing yourself up for this.”

Korine appeared on the talk show three times in the 1990s but was then mysteriously banned by Letterman. The host later explained to guest James Franco that it was a result of Korine’s last appearance.

“I went upstairs to greet Meryl Streep and welcome her to the show, and I knock on the door . . . and she was not in there,” Letterman said. “And I looked around, and she was not in there, and I found Harmony going through her purse. True story. And so I said, ‘That’s it, put her things back in her bag and then get out.’ ”

Crispin Glover

“Paul, is this the first time you’ve watched a guy die?” Letterman asks his bandleader halfway through this infamous 1987 interview.

And it only gets worse from there.

After the bizarre actor demonstrates his kung fu skills by nearly kicking a displeased Letterman in the face, the host walks off the stage.