Simpson's second album, I Am Me, was released on October 18, 2005. She wanted to incorporate the feel of music from the 1980s on the album, and unlike with her debut, she wanted to focus less on relationships and more on herself.The album debuted at number-one, selling around 220,000 copies in its first week;as of 2008, it had sold 944,000 copies in the U.S., according to Nielsen SoundScan.Its lead single, "Boyfriend", became a top 20 hit on the Billboard Hot 100 while Simpson's next two singles, "L.O.V.E." and "Invisible" (a track not featured on the album), reached the top 40. Simpson began a concert tour in late September in Portland, Oregon and appeared on the October 8, 2005 episode of SNL to promote the album. The first song she performed on the show was "Catch Me When I Fall", a ballad written about her previous SNL experience, and she thanked the crowd after her second performance. In mid-December, Simpson collapsed after performing in Japan, and was briefly hospitalized, consequently cancelling an appearance at the Radio Music Awards. The collapse and her subsequent hospitalization were attributed to exhaustion as a result of her busy work schedule.
In March 2006, Simpson won an MTV celebrity surfing invitational competition, which also featured celebrities such as Meagan Good, Jack Osbourne, Ashley Parker Angel and Tony Hawk. On April 12, 2006, she hosted and performed at the MTV Australia Video Music Awards, where she won "Best Female Artist" and "Best Pop Video" for the single "Boyfriend".She began a summer tour on June 5, 2006, with Ashley Parker Angel as the opening act.Simpson said that after the completion of the tour, she would look at film scripts and continue her acting career.Simpson was cast as Roxie Hart in the West End production of Chicago from September 25 to October 28, 2006. She received mostly positive reviews.Her performance in the show was described as "dazzling and near flawless."During this time, she began dating Peter Wentz