Renée Zellweger and Catherine Zeta-Jones are the stars of the film version of Chicago, but it's veteran character actor John C. Reilly who really steals the show — and the moviegoer's sympathy — as Amos Hart, the cuckolded husband of Zellweger's "scintillating sinner," Roxie.

The high point of his Golden Globe-nominated performance comes when he tears into "Mr. Cellophane," one of the musical's best-remembered numbers. It's a perfect match-up between actor and song: Not only does Reilly deliver a soulful rendition of the tune (which has been performed by such Broadway legends as Barney Martin and Joel Grey), but in a way, "Mr. Cellophane" encapsulates his career to date. Although he's been working steadily on stage and screen for the past 15 years, people still tend to remember him as "the guy who was in that movie last year."

The connection isn't lost on Reilly himself. "I feel a little like Mr. Cellophane [at times]," he tells TV Guide Online, "but I think it's by design. I'm not one of those people who is myself for a living. I deliberately lose myself in the roles I play."

That last part is certainly true. Whether he's portraying a lonely cop (Magnolia), a doomed fisherman (The Perfect Storm) or Jennifer Aniston's husband (The Good Girl), Reilly seems to reinvent himself in each film. While his chameleon-like acting style has made him a favorite with directors — particularly Paul Thomas Anderson, who has cast Reilly in all his movies except for the recent Punch-Drunk Love — and critics, he admits it has its drawbacks. "You start to think, 'I'm fighting for every job because no one knows who I am!' It gets a little tiring."

Finally, all that's about to change. Aside from Chicago, Reilly has featured roles in two other eagerly awaited films: the just-released Gangs of New York and The Hours. "It's like a walking resume," Reilly laughs. "I keep telling my friends, 'You can run, but you can't hide! In theaters [right now], I'll find you. It doesn't matter your demographic, I'll find you!'"