The 10 wackiest David Letterman interviews ever

1.Wacky Joaquin
Starting, of course, with Joaquin's February 2009 interview, during which he revealed that he was retiring from acting and embarking on a rap career. His shaggy beard, sunglasses at night, one-word answers to questions, and overall twiggy, skittish behavior had us seriously worried.
2. Drew flashed Dave
Drew Barrymore seems so together these days that it's easy to forget that she was once a total mess. Case in point: her 1995 interview with Letterman. It's hard to believe that she wasn't on anything when she revealed that her birthday usually makes her nauseous and talked about how liberating stripping is. Then Drew jumped on the desk and proceeded to flash Dave.
3. Madonna made us cringe
A year earlier, Madonna made quite a spectacle of herself on "Letterman." After berating Dave for being so interested in her sex life and calling him a "sick [expletive]," she said, "Aren't you going to smell them? I gave him my underpants and he won't smell them."
This was during her Goth phase, when she was rocking black hair and combat boots, and more attitude.
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4. Farrah was acting weird
In 1997, Farrah Fawcett appeared on the cover of Playboy and did a Pay-Per-View special called "All of Me." And she made an appearance on "David Letterman," which she was late for because there were "people, lots of people."
She revealed that she and her mother had to have conceived on the same day, since their children have the same birthday. But the best moment was when she got totally confused and paused for a while.
"Wow. I really thought I was looking out the window," she said, before giggling compulsively.
5. Crispin's awkward interview
Crispin Glover was so cute and innocent in "Back to the Future." But he ruined it all when he appeared on "Letterman" in 1987 to promote his movie "River's Edge."
And it wasn't just the bad wig, '70s shirt, striped pants, and platform shoes that turned the world off. "I'm a movie star," he declared, awkwardly. Then he challenged David to an arm-wrestling match.
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6. Paris squirmed
In 2007, Paris Hilton went on "Letterman" after her stint in the slammer and the whole thing was just uncomfortable. "How'd you like being in jail?" David asked, just a few seconds in. "Not too much," she replied. Yes, he also asked about the food. "It's not supposed to be good -- it's jail," she said.
7. Cher was defensive
Isn't it weird that Cher looks younger now (see the recent MTV VMA show, anyone?) than she did in her 1986 "Letterman" interview? For her 1996 appearance, she kept her hands firmly across her chest.
When David asked why she refused to come on the show for years and then relented, Cher explained, "I want to pay my hotel bill. I have a huge hotel bill. I thought I'd come on and see what this guy is like." So what did she think? "You're an [insert a not-so-nice-name for 'jerk']."
8. Courtney pulled a "Drew"
Nearly a decade later, Courtney Love went on "Letterman" wearing almost the same ensemble that Drew Barrymore sported on the show. Before she even sat down, she flashed him. Then she did it again and again, before falling off a chair.
"I learned how to flirt from watching David Letterman flirt with Sandra Bernhard. It has been the crisis of all my dysfunctional relationships ever since," she said. Yowch.
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9. Andy Kaufman's big joke
Andy Kaufman isn't known for his straight interviews. In 1982, he appeared on "Letterman" with wrestler Jerry Lawler. Why? Because part of Kaufman's shtick was wrestling women, and as such, Lawler challenged him to a match.
During the interview, Lawler slaps Kaufman, which leads to a tirade worthy of a "Real Housewife." We'll never know if this whole bit was staged.
10. Borat bombed
We know what to expect from Sacha Baron Cohen when he's in character as Borat, but David Letterman didn't seem prepared. Seems he thought he was getting an interview with Sacha proper.
When David asked about Sacha's wife, he was no doubt referring to Isla Fischer. But Sacha responded, "My wife is dead. High five. When I buy my wife, she was very nice, she cook good, she was strong on plow. But after three years when she was 15, her voice got deep and she grow much hair on chest." David was not amused.