Celebs Celebrate Halloween: See What Costumes 'True Blood,' 'New Moon,' 'Gossip Girl' Stars & More Chose!

When you work in the entertainment industry, almost every day affords another chance to play dress up. But it's not often stars get to choose their own costume, which must make October 31 an extra-special day in their book, evidenced by the plethora of celebrity Halloween costumes we spotted over the spooktacular weekend.

"True Blood" stars Rutina Wesley and Sam Trammell brought some of that Bon Temps magic to Las Vegas for the occasion — almost quite literally if you consider that Sam is dressed up as some kind of viking wizard (we were scratching our heads a little at that costume, too). Rutina, on the other hand, traded up her Merlotte's bar outfits for a black and orange pirate wench costume. Or maybe she's a gypsy and together she and Sam were able to predict the future. If only they shared what they foresaw for season three of "True Blood"!

Gossip boy Penn Badgley celebrated his 23rd birthday a day early at the Halloween 2033: SVEDKA Vodka Adult Playground Series at 1Oak in New York alongside girlfriend and costar Blake Lively. We're not really sure who or what Penn is supposed to be (we're guessing Will Ferrell in "Semi-Pro" meets '70s porn star judging by that mustache), but his gal pal sure got heart rates fluttering as a sexy, black-clad stewardess, complete with a bobbed, brunette wig.

Hey, if this acting thing doesn't pan out she could always have a career with Lufthansa. Another "Gossip Girl" incognito at 1Oak was Georgina Sparks (a.k.a. Michelle Trachtenberg), channeling Marie Antoinette in a sky-scraping white wig and plenty of ruffles.

While Manhattan's elite partied on the right coast, a pair of "New Moon" vampires let the right ones in at Veuve Clicquot's Yelloween at the Tao Nightclub at the Venetian Hotel in Sin City. The duo rocked a bird theme (intentional or not?) as Kellan Lutz was every inch the Boy Wonder in a black mask and body armor while costar Ashley Greene sported long, black waves and feathers galore as a sexy peacock.

Also living it up in Vegas was "Step Up 2: The Streets" star Briana Evigan as a belly dancer/"Dancing With the Stars" contestant (I'll let you be the judge). Not to be outdone, Briana's "Sorority Row" costar Audrina Patridge hosted her very own bash, "I Dream of Audrina" the day after Halloween at the Dusk in Atlantic City, New Jersey. And as you can guess, she is indeed dressed as a genie.

Want to see even more stars in costume? Click on any of the photos above to look through our entire Celebrity Halloween gallery including the cast of the "Today Show" harnessing the force as "Star Wars" characters, "Project Runway" alum Christian Siriano looking fierce as the Little Mermaid and Eliza Dushku and her bf Rick Fox going gangster.

Which celeb do you think had the best costume?