Duff's third album, Most Wanted (2005), comprised her favorite tracks from her previous two albums, remixes, and new songs inspired by pop-rock musicians such as The Killers and Muse. In an appearance on Total Request Live, Duff stated that it was not a greatest hits album, but that her label told her it was time to release a new album. She had more creative control over Most Wanted compared to her previous releases, co-writing the new material with vidéo sexy hilary duff producers Joel Madden and his brother, Benji, both members of Good Charlotte. The lead single, "Wake Up", became Duff's highest peaking single on the U.S. Hot 100 at the time,^[30] and its video received heavy rotation on MTV. The video for the second single, "Beat of My Heart", was also popular, but the single itself did not chart in the U.S.^[30] The album debuted at number one on the Billboard 200^[54] and became her third number one debut in Canada. An Italy-only compilation, 4Ever, was released in 2006. Duff recorded new songs for her movie, Material Girls, which included a Timbaland-produced cover version of Madonna's "Material Girl" with her sister.^[55]

During her Still Most Wanted tour, she performed in Guadalajara, Mexico, where she filmed a brief appearance on the soap opera Rebelde. She was also the guest star on The Andy Milonakis Show for its third season premiere in 2007.^{Friederike Gnädig nue id="cite_ref-65" class="reference">[66]} In April 2008, Duff was offered the lead role of Annie Mills in the CW Network's Beverly Hills, 90210 spinoff, but she turned it down because she was more interested in looking for projects outside the teen genre.^[67][68] She is also a model signed to IMG Models New York.^[69]

In September 2006, Duff released her perfume, "With Love... Hilary Duff", which was distributed by the Elizabeth Arden company. The perfume was initially sold only in Macy's in the U.S. and soon it was being sold in other regions like Japan and Canada. In 2007, Duff announced that she will be releasing a summer version of the perfume titled, "Wrapped With Love". It was released in January 2008, and a Spring Gift Set version was released in time for Valentines Day.^[89]

In early 2007, the Duff sisters lent their voices to the computer animated comedy Foodfight!, which is to be distributed by Lions Gate Films and scheduled to release in 2008. The director the film, Larry Kasanoff, said that he is "absolutely thrilled to have the Duff sisters as part of the cast".^[73] Duff also stars opposite John Cusack in War, Inc. which was released in theatres in Los Angeles and Manhattan, Friederike Gnädig nue New York on May 23, 2008. Within a month of its release, it was expanded to several more theaters around the US.^[74] On September 7, 2007, Duff confirmed on Much On Demand, that she would be filming two independent films Greta, and Safety Glass. Both movies were filmed in late 2007 and are due to be released in late 2008 or early 2009.^[75] Duff has joined the cast of a new Polish brothers comedy Stay Cool. She will co-star alongside Winona Ryder, Mark Polish, Sean Astin, Chevy Chase and Jon Cryer. She will portray the character of Shasta O'Neil, described as a sexy high school senior. The movie was filmed during July and August 2008 in Santa Clarita, California,^[76] and the film is scheduled for release in 2009.

In late 2006 Duff took legal action against an alleged stalker and his roommate.^[62][63] On November 3, 2006, Duff's stalker, Maksim Miakovsky, was arrested for threatening to kill her. He was booked on charges of making criminal threats and stalking. According to legal papers filed by Duff, Miakovsky came to the U.S. "for the sole purpose of meeting cool pics.com and becoming romantically involved with Ms. Duff".^[64] Miakovsky was being held on $200,000 bail at the Manhattan Beach jail. He was arraigned on November 7, 2006.^[64] On January 19, 2007, Miakovsky was sentenced to 117 days in jail and five years probation after pleading no contest to the charges.^[65]

Playmates Toys released a celebrity doll of her in 2004.^[87] In late 2006, Mattel released a Hilary Duff Barbie doll. As a fashion designer, she had designed clothes for Barbie dolls in the past^[88] and with the release of her doll, she joined Reese Witherspoon, Beyonce Knowles and Lucille Ball who have their own celebrity-dolls.^{nina friederike sexy id="cite_ref-designdoll_87-1" class="reference">[88]}

She has also launched a clothing line, "Stuff by Hilary Duff", and two exclusive perfume collections with Elizabeth Arden. Duff and her mother were listed as producers for the movie Material Girls,^[3] As of September 2008^[update], her upcoming films include animated comedy Foodfight!, and independent films Greta, Safety Glass haylie duff nue and Stay Cool.^[4]