For the third straight week, 50's The Massacre will claim Billboard's proverbial pole position, according to SoundScan figures. The album, 50's follow-up to 2003's Get Rich or Die Tryin', sold more than 364,000 copies, for a three-week total of almost 2.3 million units. Despite a sales plummet of more than 50 percent, The Massacre maintains its place at the top of the charts, begging the obvious question: Can 50 Cent be stopped?

According to next week's sales tally, not anytime soon. The combined musical might of U2, Gwen Stefani, Lindsay Lohan, Nelly, Snoop Dogg, Destiny's Child, Good Charlotte and Ashanti, in the form of Now That's What I Call Music! Volume 18, will prove itself to be the strapping rapper's toughest opponent -- with first-week retail scans of nearly 339,000. But in the end, Now 18's still no match for the likes of 50.

The week's other big debuts -- Baby Bash's Super Saucy (#11), Brooke Valentine's Chain Letter (#16), Crosby, Stills and Nash's Greatest Hits (#24), the Kaiser Chiefs' Employment (#86) and Daft Punk's Human After All (#98) -- will all infiltrate the top 100, but lag far behind The Massacre.

Sales of surfer-turned-acoustic-rocker Jack Johnson's hit In Between Dreams will fall just below the 100,000 mark to take a distant third, while Green Day's acclaimed American Idiot will climb one position on the Billboard sales chart to #4, with sales of close to 76,000 in its 26th week of release. Not surprisingly, sales of Jackson's 2003 album On and On have picked up in the wake of his surging popularity: The LP moves from #162 to 135 on next week's chart, with sales swelling 23 percent (pardon the surfing puns).

Former G-Unit foot soldier the Game's The Documentary slides two spots to #5, with more than 67,000 records flying from retail shelves. Kelly Clarkson's Breakaway is right behind Compton's finest, coming in at #6 with more than 66,000 scans. Jennifer Lopez's latest, Rebirth, takes #7 with somewhat disappointing sales; with little more than 60,000 albums sold, Jenny's record has barely moved 408,000 copies after its third week of release.

My Chemical Romance, who will be opening for Green Day next month, have breached the top 50 with their album, Three Cheers for Sweet Revenge. Powered by the band's two popular videos -- "Helena" and "I'm Not Okay (I Promise)" -- sales of the album climbed 10 percent last week, with just over 20,000.

The Napoleon Dynamite soundtrack got a 75-percent sales surge that a representative at SoundScan said was due to the label's belated request to combine digital sales (i.e. iTunes and other digital formats) with physical album sales. The album re-enters the Top 200 at #159 on more than 6,000 copies sold last week.

Honor Roll = More Sales?

Next week's chart will feature several big movers, including U2's How to Dismantle an Atomic Bomb. The sales spike came the week after the Irish rockers were inducted into the Rock and Roll Hall of Fame. With more than 23,000 scans, a 26-percent increase over the previous week's sales, U2 will secure the #39 chart position.

Kanye West, who took home Outstanding New Artist honors from last weekend's NAACP Image Awards, saw a slight bump in sales for his College Dropout. The album climbs eleven spots to #93, with more than 11,000 units sold.

Next week could mark the end of an era, as 50 Cent's supremacy will face competition from Queens of the Stone Age's Lullabies to Paralyze, Moby's Hotel, Frankie J's The One and Tweet's It's Me Again. Only time will tell if 50's chart dominance can withstand further attacks, but if the trail of records left in his commercial wake tell us anything, it's that 50 isn't going to go silently.