Paris Hilton
The hotel heiress guests on the Oct. 8 episode of Supernatural as a demon who feeds on the disorienting power of celebrity.
Charisma Carpenter
The former Buffy star plays a Mord-Sith named Triana in the season-two premiere of Legend of the Seeker, airing Nov. 7 in syndication.
Tyra Banks
The CW gets a little synergy going when the Top Model host appears as herself on Gossip Girl.
Kristin Chenoweth
The Broadway baby and former Pushing Daisies star comes to Glee beginning in episode five, airing Sept. 30. Her character, April Rhodes, plays an alcoholic vocal coach who stirs up the glee club kids.
Hilary Duff
The Disney doll appears on Gossip Girl this season as Olivia Burke, a movie star who falls in love with Penn Badgley's Dan Humphrey.
Rumer Willis
The celebrity scion continues her tour of every series that will have her. She joins 90210 this season as a lesbian high schooler named Gia who works at the Blaze with Navid and Adrianna.
Rumer Willis
Bruce and Demi's daughter appeared on The Secret Life of the American Teenager as Heather, a pregnant teenager with an eye for Ben (Kenny Baumann).
Katie Holmes
What? Reality shows can have stuntcasting, too. Mrs. Tom Cruise appeared on the 100th episode of So You Think You Can Dance to support the Dizzy Feet Foundation.
Taylor Swift
The country songbird guested on CSI as a doomed young woman who lived at a motel.
Mary-Kate Olsen
The Olsen twin who still acts joined Christina Applegate's sitcom Samantha Who? for a one-ep stint as unredeemable bad girl Natalie.
Lauren Conrad
The reality star played herself in the second-season finale of Greek. She appeared in a dream to Spencer Grammer's Casey Cartwright and offered spiritual guidance.
Rumer Willis
On Army Wives, Rumer played a wounded soldier's young wife. Her character was befriended by kindly nurse Denise (Catherine Bell). What can we say? We're obsessed with Rumer's impressive and slightly frightening ambition and ancillary work ethic.
Lauren Conrad
Oh look, it's L.C.! Again! The Hills star played herself at a party attended by the Privileged twins, Rose and Sage (Ashley Newbrough).
Oprah Winfrey
We love you, Liz Lemon (Tina Fey), but shut up. Borpo is talking.
Nicole Richie
Fashion designer and onetime reality star Nicole Richie and her onscreen hubby, Ben Savage, both kicked ass when they dropped by Chuck to remind Sarah Walker (Yvonne Strahovski) of the torments of high school.
Katie Holmes
The erstwhile Joey did a favor for her old Dawson's Creek show runner, Greg Berlanti, and appeared on his ratings-challenged ABC drama, Eli Stone. (She even did a little dream-sequence song-and-dance number.)
Lindsay Lohan
It didn't turn out so well in the end, but when LiLo first landed a gig on Ugly Betty as mean girl Kimmie Keegan, everyone thought the wayward actress had finally gotten a real job.
Victoria Beckham, Vera Wang
The former Spice Girl and the celebrated designer guest-starred in Ugly Betty's "A Very Posh Wedding" episode, wherein Wilhelmina (Vanessa Williams) tried to seal the deal with tycoon Bradford Meade (Alan Dale).
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