Even though New York First Mistress Sandra Lee is forever partial to Halloween—if you don't know why, do yourself a favor and click here to find out—she still made time to visit tonight's Late Night and prepare a Thanksgiving meal with Jimmy Fallon. And by "Thanksgiving meal," I mean "a gross-looking Bailey's martini and some cornbread stuffing with a can of Campbell's chicken rice soup in it," among other monstrosities. Aunt Sandy, God love her.

Justin Bieber stopped by the Late Show this evening for a chat with David Letterman. At one point, Bieber noted that he'd been to "every continent." But after being challenged by Letterman to actually name each of them, Bieber was less than successful. See that, plus Letterman telling Bieber that a photo of him looks like Marie Osmond, in the above video.

Bravo is all set to announce plans to take Andy Cohen's Half-Hour Make Me Famous Hour from its current Sunday and Monday airings to five nights a week. His plan for global media domination is working! Yes, Watch What Happens Live will now run Sunday through Thursday.

Regis Philbin bids farewell to Live! tomorrow, but he still had time to stop by tonight's Late Show. Philbin stuck around for much of the hour, during which he and David Letterman talked about making out with each other, the possibility of Jerry Seinfeld coming between them, and more. Then, Philbin crashed the Vespa that Letterman bought for him as a retirement present. Here's our video of highlights.

Conan O'Brien ended his week-long stint in New York with a bang tonight: He officiated at the same-sex wedding of a staffer and aired the ceremony on his TBS talk show. Scott Cronick works as Conan's costume designer and he was accompanied down the aisle by Bravo's Andy Cohen before tying the knot with his partner, David Gorshein, under a chuppah that had been set up on the stage. Then it was up to Conan to make it official, as you can see in this clip from the show.

When Canadian pop star Justin Bieber isn't calling for the imprisonment of U.S. senators with whom he disagrees on the finer points of copyright law, he occasionally releases music. Like his new Christmas album, Mistletoe, which Bieber promoted on The Tonight Show on Monday, an appearance that mostly consisted of the teen idol uttering the word "like" again and again and again. Don't believe us? Watch the video and see for yourself.

Salma Hayek has kept a relatively low profile since having a child with (and eventually marrying) French billionaire Francois-Henri Pinault, so she had lots to discuss with David Letterman when she stopped by tonight's Late Show to promote her new film. Here are highlights of their lively chat, including her struggle to quit smoking, her four-year-old daughter's adult-like attitude, and Letterman's obsession with Hayek's earrings.

President Obama's reliance on a teleprompter to deliver big speeches has long served as fodder for his political opponents. So the news this morning that a truck carrying the presidential podium had been stolen was ready-made material for late-night TV hosts like, say, Conan O'Brien, who aired this video tonight to demonstrate what happens when the president is forced to go it alone.

Tracy Morgan got into some hot water back in June for saying during a stand-up show that he'd stab his son to death if he were gay. Morgan apologized more than once for his remarks in the weeks that followed. But he didn't exactly help his case during an interview on tonight's Late Show.

Remember when Sarah Jessica Parker went on the Late Show last month and told David Letterman a rambling story about Russia? Replace the Late Show with Watch What Happens Live, David Letterman with Andy Cohen and Russia with the Real Housewives, and you'll have described what happened on Bravo tonight. Here's a highlight reel of Parker's manic, albeit pretty adorable, appearance.

Well, this was uncomfortable. On tonight's Late Show, David Letterman interviewed '80s movie star-turned-alcoholic flameout Sean Young. The chat was bizarre from the onset—Young described disciplining her teenage sons with a horsewhip—and then turned downright sad as Young pleaded for work with anyone who'd consider hiring her. The saddest part? The video clip that Young shared of her dressed up in a Catwoman suit, screaming "I'm not crazy!" to random passers-by.

While many TV newsmen aren't good at anything else, a one-trick pony Brian Williams is not—and he's got a reel full of everything from cameos on 30 Rock to slow jams with Jimmy Fallon to prove it. The NBC Nightly News anchor does best, though, when there's no agenda or script, which is why his appearances with David Letterman on the Late Show are often so memorable.

Anderson Cooper probably woke up this morning thinking he'd only be on two television shows by the end of the day. But then the opportunity came along to appear on a third program—and promote his new daytime talk show in the process—and he couldn't resist.

In addition to being a possible Republican presidential candidate, New Jersey Gov. Chris Christie is really fat. So naturally, in recent days Christie's been the butt of jokes made by everyone from Chris Matthews to David Letterman, who on tonight's Late Show delivered a top 10 list of "ways the country would be different if Chris Christie were president." Here's a clip of the segment.

Modern Family star Sofia Vergara stopped by the Late Show on Thursday to gloat to David Letterman about her show's big night at the Emmys. And while I suspect any conversation between Letterman and Vergara would be entertaining, this one was made even better by the fact that they kept confusing each other throughout it.

On the eve of its premiere, X Factor judge Paula Abdul—aka the human incarnation of a lost dog finally seeing its owner again—wandered onto Tuesday night's Late Show, where she was asked by David Letterman to explain the differences between The X Factor and American Idol. She, uh, tried.

Ahead of Wednesday's premiere of The X Factor, Simon Cowell is in full promotional mode. Tonight's PR pit stop brought Cowell to The Tonight Show, where he shared some brutally honest opinions of his three X Factor co-judges to Jay Leno.

You know how Jay Leno's lips are always firmly planted on his guest's behind, no matter who it is? How publicists enamored with Leno's softball predictability are always eager to book their clients on The Tonight Show? And how Leno rarely, if ever, challenges the answers a guest provides to the questions he asks? Well, that changed on Friday night. How so? Two words: Michele Bachmann.

We haven't seen much of Charlie Sheen since earlier this year—when we didn't see much that wasn't Charlie Sheen—but the former Two and a Half Men star stopped by The Tonight Show on Thursday ahead of next Monday's airing of his Comedy Central roast.

On tonight's Report, Stephen Colbert's BFF for six months, Jimmy Fallon, stopped by to bask with him in the glory of their unlikely bond. But then they realized that their friendship was actually supposed to end 12 days ago, so the two men made haste to hate. Luckily for Colbert, at least, a new prospective BFF was already waiting in the wings, ready to take Fallon's place.