Champions of the modern big-budget video game, Activision took over the STAPLES Center in Los Angeles for a preview event of epic proportions. With little signage and indication of exactly what would take place, throngs of lucky invitees piled into Downtown’s STAPLES Center, greeted by the most unusual phenomenon imaginable at the venue–free food and beer at every single corner the building. That’s right, for whatever reason all the typically overpriced, concert junk food and beverages were entirely on the house. As the crowd tried to make sense of the situation, security kept all gates into the main floor blocked. What was unmistakeably Eminem could be heard on the other side of the curtain.

Check out video clips and more after the jump!

Long-time mxdwn favorite DJ Z-Trip got the evening off to an upbeat start blend rock and hip-hop in fun combinations to get the crowd going (Survivor’s “Eye of the Tiger” with DJ Shadow’s “Organ Donor,” Metallica’s “Seek and Destroy” and Ozzy Osbourne’s “Crazy Train”). After a vignette promoting the upcoming DJ Hero 2, Deadmau5 appeared on one riser at the front of the stage catwalk donning his standard blue mouse head mask. A short set deftly put down, his riser lowered and on the flanking side David Guetta rose from another. Guetta played to the crowd with snippets of the Black Eyed Peas’ “I Got A Feeling” while Deadmau5 remixed bits of Daft Punk’s “Harder Better Faster Stronger.”

Usher took the stage next, playing four songs including “Caught Up” and dance club favorite “Yeah.” And speaking of the Black Eyed Peas, will.i.am joined Usher for a short verse during his finale. Z-Trip returned briefly to help promote Tony Hawk’s new skateboarding game Tony Hawk Shred. Tony Hawk showed up in the middle of the arena with a gaggle of pro skaters, but a tech malfunction caused them to not be able to demo in person what they had planned.

Next, a video played promoting a new installment of Guitar Hero entitled Guitar Hero: Warrior of Rock. The video introduced some of the in-game characters and then sequed into the four of them singing the Opening to Queen’s classic “Bohemian Rhapsody.” Once the song reached it’s opening verse, a stunning surprise was revealed in that none other than Tool/Puscifer lead singer Maynard James Keenan was behind the voice. Decked out in a full black suit and shades, Keenan gently cooed throug the song’s refrain of “nothing really matters.” And fitting of the grand scope of the song, as the lights continued to brighten, Keenan’s support of a full orchestra and choir became visible. A separate riser brought up a guitarist (possibly Billy Howerdel? scratch that, it was in fact Billy Howerdel) to complete the song’s guitar solo and decrescendo. The whole night would have been worth this moment alone.

Jane’s Addiction took to the stage next with new bassist Duff McKagan. Lead singer Perry Farrell sounded as if he was straining to sing during “Been Caught Steeling,” but the powerful “Mountain Song” came through with the force and spirit they’re legendary for. Not to be outdone, another surprise backed by the orchestra was unveiled, Soundgarden’s Chris Cornell singing a subdued version of “Black Hole Sun.” Cornell sounded fresh and vital backed with proper instrumentation. Cornell alternated between the soft murmur of the song’s chorus and the shrill call of “Black hole sun!”

True Crime Hong Kong was shown next on the massive video wall adorning the back of the stage. The video wall itself must have cost a daunting fortunate as it was over one hundred feet wide. The gritty backdrop of the mafia/cop straddling game introduced Pharrell and his band N*E*R*D. Even though the band didn’t play to their strongest material, Williams deserves a lot of credit for working hard to put over Activision for so generously holding the event and fighting to hype up the crowd. A curious inclusion of singer Rhea followed, which was nothing more than her shaking her ass with a gaggle of backing dancers pretending to play a guitar.

And for the finale, Activision debuted it’s in-game preview of Call of Duty: Black Ops. The footage highlighted the game’s ability to shift between first-person action on foot into controlling a hind helicopter and then… well… blowing the crap out of everything in site. As the video came to its climax, some of the loudest pyro popped on all sides of the building, acting as the explosion of the helicopter. The one-and-only Eminem ended the night with a six-song set. From the get-go, the once-named Slim Shady looked postively ferocious, as if the whole world was watching this performance and checking to see if he’d fail. “It Was Just A Dream” and “Not Afraid” delivered intense fire and energy, ramping the crowd’s interest up. Eminem paused for a moment to thank the crowd, openly stating, “Thank you to all my fans for sticking by me.” And for an even yet another surprise, he brought out Rihanna to do a ferocious number called “Love the Way You Lie.” There was only one encore, but it was a doosy, the thudding guitar and mounting excitement of “Lose Yourself.” Even though he didn’t sing the chorus live, the crowd was elated at each line of, “You better lose yourself / in the moment / you own in / you better never let it go.” For a man who has struggled in recent years to continue his meteoric path of success, this was a show-stopping performance. Eminem was defiant and charismatic in just the right way. His stage presence–and an angry, determined, look in his eye–easily made his set the performance of the evening.

UPDATE: Travis Barker was the drummer for Eminem’s performance. Additionally Eminem debuted a new song “Won’t Back Down.”

For a promotional event, this was something special. Activision either is doing quite well with their recent endeavors, or they mean to be. And either way, they deserve all the credit and press that comes from this. This event was remarkably generous and understated given its obvious desired effect. No cheesy MCs shilled for product. Only the talent and the occasional video clips played stumped for the company’s aim. Just like their Guitar Hero Metallica event at SXSW 2009, this was pure fun and jaw-droppingly cohesive and exciting. And to boot, it featured some of the best stage production and pacing possible. A stellar start to E3 week, and sure to be the talk of the convention.

We’ll post videos of the action once they become available.