The late-night circuit is usually a well-oiled Hollywood hype machine through which movie stars and hot-shot directors can safely plug their latest films. Every once in a while, though, things go off the rails, a phenomenon that seems to happen with a bit more frequency on Letterman, whose arched detachment can allow those moments to play out in all their awkward glory.

In honor of the "Late Show" host's announcement that he plans to retire in 2015, here are five of the most memorable movie guests to grace Letterman's couch. If there's a common thread running through these appearances — other than Letterman's acerbic wit — it's that in the world of late-night TV, one doesn't need an enduring movie to make a lasting impression.

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Drew Barrymore

Back in 1995, Drew Barrymore was sporting close-cropped, bleach-blond locks and playing crazy girls in movies like "Mad Love" and "Boys on the Side" when she gave Letterman an infamous birthday present.

After regaling Letterman with tales of a "nude art performance dance place" run by a woman named Ute, the 20-year-old actress hopped up on his desk, gyrated for a moment and flashed the late-night host, who was rendered briefly, uncharacteristically speechless.

When Letterman finally came to, he deadpanned, "Remember the night Morley Safer was here [and] pulled the same thing?"

Crispin Glover

Before Letterman made the move to CBS, he hosted NBC's "Late Night With David Letterman," a show on which "Back to the Future" actor Crispin Glover became an unlikely nemesis. Glover's first of three bizarre appearances came in 1987, when the actor was promoting "River's Edge" but showed up in character as an awkward young man from the "Rubin and Ed"--and a character unknown to most viewers.

After challenging Letterman to an arm-wrestling match, Glover demonstrated his karate prowess and nearly kicked Letterman in the face, prompting the host to walk off and saying he was "going to check on the Top 10."

Glover returned to the show about a month later and was awkwardly giddy, prompting Letterman to say, "You know, you're seconds way from being slapped," before adding, "I'm just kidding."

Finally, in 1990, Glover came back on "Late Night" and claimed that it was a doppelganger, not him, who appeared the previous two times.

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Harmony Korine

Another guest with multiple memorable Letterman appearances is "Spring Breakers" director Harmony Korine, who took a seat on Letterman's couch in 1995 to promote "Kids," in 1997 to flog "Gummo" and in 1998 to plug his book "A Crack-Up at the Race Riots."

Korine's spacey behavior and non sequiturs frequently exasperated Letterman, who in the '95 interview said, "You know, I could pretty much have this conversation by myself," and quipped in '98, "This, by the way, is why they invented childproof caps."

Last year, "Spring Breakers" star James Franco visited "The Late Show" and persuaded Letterman to reveal that Korine was once banned from the show when, during a planned fourth appearance, he was supposedly caught rifling through Meryl Streep's purse.

Joaquin Phoenix

Having announced he was retiring from acting to pursue a career as a rapper, Joaquin Phoenix showed up on "The Late Show" in 2009 in dark sunglasses and a heavy beard, then offered only mumbled, monosyllabic responses to Letterman's questions.