PHOTOS: WireImage

On Thursday night in NYC, Samsung celebrated the launch of its Samsung Experience Shops at Best Buy locations nationwide, as well as the arrival of the brand new Galaxy S 4 smartphone, with a big ‘ole megabash!

To get the party started, Rev Run (of Run DMC) joined DJ Ruckus for a 45-minute set, after which guests were treated to an intimate concert by Bruno Mars, who played fan favorites including “Locked Out of Heaven,” “Marry you,” “Treasure” and “When I Was Your Man.”

At the concert, guests – including Rosario Dawson, singer Jason Derulo, Katrina Bowden (30 Rock) and Vincent Piazza (Boardwalk Empire) – were treated to an interactive experience resembling a giant Samsung Experience Shop featuring all of Samsung’s hottest new technology such as the brand new Galaxy S 4 smartphone and Galaxy Note 8.0 tablet, as well as the Galaxy Camera, the Galaxy Note II and more.

It’s one of MJ‘s favorite shows of the year — the Victoria’s Secret Fashion Show – and it airs tonight, December 4th at 10pm on CBS!

 This year’s show features musical acts Rihanna, Bruno Mars, and Justin Bieber and, of course, the beautiful Victoria’s Secret Angels.

In case you missed MJ‘s AXSLive coverage of the backstage or the pink carpet where we chatted with just about everyone, those clips appear after the jump!

Everyone loves Bruno Mars, but in this new Funny or Die video, the R&B singer shows you “whattaman” he really is…

Watch it now for a good laugh!

PHOTO: Marion Curtis/Starpix

Hollywood hunk Zac Efron got all cleaned up for the Cinema Society & Men’s Health screening of ‘The Lucky One’ in the Big Apple! Teaming up with co-star Taylor Schilling, the two seemed to be having a blast as the Crosby Street Hotel!

“Tron” starlet Olivia Wilde stepped out incognito sporting new blonde locks for the Shorts Filmmaker Party at the new BOMBAY SAPPHIRE House of Imagination event. Reportedly for an upcoming movie role, the newly-blonde beauty appeared fresh faced and relaxed as she mingled and celebrated in support of her close friends in the Short Film Industry.

Emma Watson, wearing an embroidered Johnny Was blouse, was spotted with new flame Will Adamowicz at the Florence and the Machine performance at Coachella this week.

Actor Robert DeNiro was spotted toasting friends and supporters with a glass of Champagne Nicolas Feuillatte at the New York Academy of Art’s Tribeca Ball, where he was this year’s guest of honor. Looking dapper and proud, Mr. DeNiro accepted the honor amongst a stylish crowd of attendees that included Mary Kate Olsen, Kim Cattrall, Solange Knowles, and Padma Lakshmi.

Goldie Hawn, who was among the honorees for her efforts with The Hawn Foundation caught up with close friend, Donna Karan and President and CEO of Turnaround Dr. Pamela Cantor. Chris Cuomo acted as event emcee and Bronson Van Wyck designed the gala at the Turnaround For Children’s Third Annual Impact Awards Dinner at The Plaza Hotel in New York City.

Chris Masterson spotted with a group of friends at AGENCY this week listening to resident DJ Travis Emmons. Also spotted was Mark Salling, making his way into the venue incognito, donning all black and a beanie around 12:30 AM.

The stars are flocking to California’s hottest luxury nail salon Bellacures. Everyone from Jennifer Garner to Hilary Duff and what almost seems like the entire cast of Glee, including Lea Michelle and just this past week Dianna Agron and Naya Rivera. Dianna’s purple nails added a pop of color to her black and white outfit.!

Despite the boiling temperatures, Ke$ha did a lap around the pool at The Saguaro “Desert Weekender” pool party presented by HELLO STRANGER and dubFrequency, stopping to take a photo before heading out to Coachella Music Festival.

FOR MORE STAR SIGHTINGS THIS WEEK, KEEP READING…

© RD / Kabik / Retna Digital

Celebrities hosted parties from New York to LA and we have your roundup of the hottest parties from the hottest stars!

Fergie attended the New Year’s Eve party at The Mirage’s 1 OAK, planting a kiss on husband Josh Duhamel at midnight. Her Black Eyed Peas bandmate, Will.i.am., was at the Strip nightclub Surrender at the Encore at Wynn Las Vegas!

“Jersey Shore” star Vinny Guadagnino hosted Joonbug.com Beat the Beats New Year’s Eve party at the AMC 34th Street movie theater in NYC, where the website transformed the movie theater into a club for one night only!

Lady Gaga was the special guest of Mayor Michael Bloomberg and did the honors of dropping the ball in Times Square. Gaga’s performance as part of Dick Clark’s Rockin’ New Year’s Eve, which also featured Ryan Seacrest and Jenny McCarthy, will be broadcast both in the United States and in Japan. Other celebs performing in Times Square as part of MTV’s New Year’s Eve special included Demi Lovato, Selena Gomez and Jason Derulo.

DJ-to-the-stars DJ Cassidy manned the 1′s and 2′s at Diddy‘s private house party in Miami Beach.

Robin Thicke shared his sultry musical stylings at a performance at the Delano Hotel in the MIA. His wife, Paula Patton, was also there for a kiss at midnight!

John Legend rang in the new year in style with a performance of his smooth, R&B sound at the Pearl at the Palms Casino Resort!

KEEP READING FOR MORE NEW YEARS EVE 2012 STAR SIGHTINGS…

Bruno Mars can do no wrong!

Watch the R&B crooner perform his latest hit “It Will Rain” (from the Twilight Breaking Dawn Part 1 Soundtrack) on The X-Factor!

Totally chilling performance! On another level! Watch it now:

She of course sang her hits like “Too Little (Too Late)” and “Leave (Get Out)” (and even her new track “Disaster”) but what really got the crowd excited at Boston’s Hard Rock Cafe the other night?

JoJo‘s stripped-down acoustic performance of Bruno Mars‘ hit song “Grenade!”

Check out a clip from JoJo‘s performance!