Jack & Jill wasn't her first TV job, she has also appeared in Law & Order, Seinfeld, Spin City, The Single Guy, and Central Park West.Future projects include Changing Lanes with Ben Affleck and Samuel L. "as in Long list of movies I've appeared in" Jackson, and High Crimes with Ashley Judd and Morgan Freeman. In 2005, Peet appeared in the play This Is How It Goes, filling in for Marisa Tomei at the last minute after six days of rehearsal. The same year, was released Woody Allen's tragicomedy Melinda and Melinda – starring Peet – which was given a limited release in the United States on March 18, 2005. Peet had the lead role with Ashton Kutcher in the romantic comedy film A Lot Like Love. The film is about two people whose relationship slowly evolves from lust to friendship to romance over the course of seven years. A Lot Like Love received mixed reviews and was a box office success. Los Angeles Times stated that Peet "is charming and charismatic without being cloying or artificial.
" Her on screen chemistry with Kutcher was either criticized or praised by a number of critics. Peet was nominated for the "Choice Movie Actress: Comedy" at the 2005 Teen Choice Awards.She co-starred alongside George Clooney in the thriller film Syriana, which was based loosely on former Central Intelligence Agency agent Robert Baer and his memoirs of being an agent in the Middle East. In Syriana her character was Julie Woodman, the wife of Brian (played by Matt Damon). The film was released theatrically in November 2005.In February 2006, she performed in Neil Simon's Broadway production of Barefoot in the Park. Later in 2006, she starred in the romantic drama film Griffin & Phoenix, a remake of a 1976 ABC TV movie, where she played the role of Sarah Phoenix, a terminally-ill woman living life to the fullest. Peet was a member of the cast of the television series Studio 60 on the Sunset Strip, which premiered on NBC on September 18, 2006. She starred with Matthew Perry, with whom she had worked in The Whole Nine Yards and The Whole Ten Yards, and Sarah Paulson, with whom she previously co-starred in Jack & Jill. In Studio 60, Peet's character Jordan McDeere was the newly-appointed president of the National Broadcasting System (NBS). In 2007, she received a Satellite Award nomination for Best Actress – Television Series Drama for her performance in the show.In 2007's The Ex, a romantic comedy, Peet played an attorney who stays home to raise a new baby. The film was released on May 11, 2007 and also starred Zach Braff, Charles Grodin and Jason Bateman. The film generally received negative reviews from critics and had an international gross of $5,142,074.
She next appeared as an FBI agent in The X-Files: I Want to Believe in 2008. She was cast in Nigel Cole's low-budget independent Five Dollars a Day (2008), in which she starred as a beautiful young woman named Maggie, who is the girlfriend of Alessandro Nivola's character. The film opened at the 2008 Toronto International Film Festival. Actors Christopher Walken and Sharon Stone also co-starred in the film. Also that year, Peet released the crime drama film What Doesn't Kill You, in a limited release. Her character was Stacy Reilly. The film received generally favorable reviews and Peet's performance was praised by Lisa Schwarzbaum of Entertainment Weekly, who wrote that she "is terrific as Brian's worn-down wife, sick of seeing her man disappear before her eyes."Peet starred in 2012, a 2009 disaster film directed by Roland Emmerich, alongside John Cusack and Danny Glover. In the film, she portrayed the character of Kate Curtis, a medical student and Jackson's ex-wife. The film received mixed or average reviews from critics, but had a $769,679,473 worldwide gross, becoming Peet's biggest success at the box office. In an interview with Femail, she said about the film: "this movie is like going on a roller coaster. Though I can't anymore myself, I get sick! But it's a controlled way of scaring yourself. So in a safe, controlled environment, you can really enjoy being scared. In a masochistic way." In 2010's independent comedy-drama film Please Give, Peet co-starred with Catherine Keener and Rebecca Hall; she played a self-centered cosmetologist named Mary. Please Give received a limited release in March 2010 after it was screened out of competition at the 60th Berlin International Film Festival. The film received critical acclaim; Ethan Alter of Film Journal International wrote that Peet "does career-best work here ." Peet and the other Please Give cast members received a Gotham Award nomination for Best Ensemble Cast. She guest appeared in the television series How I Met Your Mother episode "Jenkins", playing the title character.Peet next provided the voice for Rayna, one of the main characters of the 2010 animated educational sci-fi adventure film Quantum Quest: A Cassini Space Odyssey, which was opened on January 13, 2010 in the United States. Peet joined the cast of the live-action family adventure film Gulliver's Travels. She appears with Jack Black, Jason Segel and Emily Blunt. The film was released on December 22, 2010 in 3D. Her character is Darcy Silverman, Jack's editor, and potential love interest. Peet was cast as a lead in NBC's Bent. The series was cancelled after six episodes on May 11, 2012.