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 Friederike Gnädig nue 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.^{cool pics.com 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]

Duff and her pet dog Lola made an appearance in the Electronic Arts game The Sims 2: Pets, which was released on October 2006. In console versions of the game, Duff's character visits public areas and allows the players to let their Sims socialize with her and Lola.^[90] Animal rights' organisation, "Animal welfare league" have criticised Duff and celebrities such as Paris Hilton Friederike Gnädig nue and Jessica Simpson for displaying their dogs as fashion accessories rather than pets.^[91]

Duff began dating singer Aaron Carter in 2001. They met on the sets of Lizzie McGuire, during Carter's guest appearance in a Christmas episode. The relationship lasted two years.^[92][93] It was reported that Carter left Duff for Lindsay Lohan, but soon broke up with Lohan and resumed dating Duff. Carter later cool pics.com stated that he also cheated on Duff with her best friend, and that Duff "got her heart broken" and he was "sorry" for his actions.^[94] On March 23, 2007, Claymation facsimiles of Duff and Lohan appeared on the celebrity wrestling series Celebrity Death Match episode "Where's Lohan?". Duff and Lindsay Lohan were later reported to have been involved in a "feud" with each other over their relationship with Carter.^[95] In 2007, Duff and Lohan had reconciled. Lohan attended the release party for Duff's album Dignity and Duff told People magazine that she thought Lohan was "fun" and "a nice girl".^[96]

Duff co-wrote the material for her third studio album Dignity, along with Kara DioGuardi, who co-produced the album with Rhett Lawrence, Tim & Bob and Richard "Humpty" Vission. Duff stated that compared to her previous music, it is "more dancey" and makes use of more real instruments. She said, "I don't know exactly how to explain what we're doing, but it's fun and funky and different, something new for me. It's really cool".^[70] hilary duff naked She also described the album's sound as "a little less pop-rock and more electronic-sounding".^[71]

Duff has expanded her repertoire into pop music, with four RIAA certified Platinum albums and over thirteen million albums sold worldwide.^[1] Her first studio album, Metamorphosis (2003), was certified triple platinum and she followed it up with two more platinum albums, Hilary Duff (2004) and Most Wanted (2005). Duff's last studio album, Dignity, was released in April haylie duff nue 2007 and was certified Gold in August 2007.^[2]

Duff later told MuchMusic that she did not say the quotes attributed to her in the article and that the subject was "definitely not something that I would talk about..."^[99] Duff and Madden broke up in November 2006.^[100] The same year, Duff's parents separated after 22 years of marriage, due to infidelity on the Raise your voice bloopers part of her father. She wrote about the pain caused by the separation in her songs "Stranger" and "Gypsy Woman".^[101]