(1999), and as gregarious villain Eric Knox in Charlie's Angels (2000), Rockwell won the then-biggest leading role of his career as The Gong Show host Chuck Barris in George Clooney's directorial debut, Confessions of a Dangerous Mind (2002). Rockwell's performance was well-received, and the film earned generally positive reviews. Rockwell has also received positive notices for his role opposite Nicolas Cage in Ridley Scott's Matchstick Men (2003), with Entertainment Weekly calling him "destined by a kind of excessive interestingness to forever be a colorful sidekick." He received somewhat more mixed reviews as Zaphod Beeblebrox in the film version of The Hitchhiker's Guide to the Galaxy (2005). He then had a notable supporting role as Charley Ford, brother of Casey Affleck's character Robert Ford, in the well-received drama The Assassination of Jesse James by the Coward Robert Ford (2007), in which Brad Pitt played the lead role of Jesse James. According to an interview on The Howard Stern Show, director Jon Favreau considered casting him as the titular character in Iron Man as the studio was initially hesitant to work with Robert Downey Jr., who had been considered for his role in The Hitchhiker's Guide to the Galaxy. Rockwell eventually appeared in Iron Man 2, released in 2010, as Tony Stark's rival weapons developer, Justin Hammer. He is said to have accepted the role without reading the script. He had never heard of the character before he was contacted about the role and was unaware that Hammer is an old man in the comic books. In addition to big-budget feature films, Rockwell has also appeared in indie films such as The F Word and played a randy, Halloween-costume-clad Batman in a short, Robin's Big Date, opposite Justin Long as Robin. He also starred in the film Snow Angels (2008) opposite Kate Beckinsale. He has worked on several occasions with the comedy troupe Stella (Michael Ian Black, Michael Showalter and David Wain), making cameo appearances in their short films and eponymous TV series. Rockwell played Victor Mancini in the film Choke (2008), based on the novel by Chuck Palahniuk. Critic Roger Ebert said of his performance that he "seems to have become the latter-day version of Christopher Walken – not all the time, but when you need him, he's your go-to guy for weirdness." In 2007, Rockwell guest-starred in the web series Casted: The Continuing Chronicles of Derek Riffchyn, Greatest Casting Director