Ashlee Simpson may be a record-industry rookie, but she has done something that big sister Jessica hasn't been able to do: release an album that debuts at No. 1 on the Billboard album chart. That's what the newly minted MTV reality star did with her ''Autobiography,'' which sold 398,000 copies last week, according to SoundScan. That was enough to dethrone last week's champ, Jimmy Buffett's ''License to Chill,'' which dipped to No. 2 in its second week and sold another 148,000 discs. It was also enough to beat another new release, Van Halen's ''The Best of Both Worlds.'' The hits collection, so titled because it includes songs from both the David Lee Roth and Sammy Hagar heydays (sorry, Gary Cherone), entered the chart in third place and sold 138,000 records.
After nine weeks on top of the charts and six weeks in second place, Usher's ''Confessions'' dipped to fourth place on sales of 113,000. Holding in fifth place was Gretchen Wilson's ''Here for the Party,'' which shifted another 89,000 units. Lloyd Banks' ''The Hunger for More'' slid three slots to sixth place. Avril Lavigne's ''Under My Skin'' slipped one spot to seventh. Prince's ''Musicology'' rose one notch to No. 8. Down two was No. 9 finisher ''Horse of a Different Color'' by Big & Rich, while the soundtrack to ''A Cinderella Story'' dropped one place to No. 10.