Mirren took home the award for her portrayal of British monarch Elizabeth II and Whitaker for his role as ruthless Ugandan dictator Idi Amin.

    "Little Miss Sunshine" won the prize for best film ensemble, the guild's equivalent of a best-picture award.

    It seemed the soft-spoken Whitaker was struck speechless, stumbling over some awkward words of gratitude.

    "I want to thank you for allowing me to have a moment like this," Whitaker said.

    Eddie Murphy and Jennifer Hudson won supporting-acting honors as soulful singers in "Dreamgirls," reinforcing their status as Oscar front-runners as well.

    At first, Murphy seemed to take a cue from Whitaker and began his thank-you speech in a somber tone of voice, but his comic roots soon betrayed him.

    "What a tremendous honor to be recognized by one's peers. I've been acting for some 25 years now and this is a tremendous honor," said Murphy, talking in a British accent.

    "No, I'm sorry," said Murphy, cracking up in laughter. "I feel goofy up here, 'cause I don't be winning stuff."

    As a powerhouse vocalist in "Dreamgirls," Hudson continued her breakneck rise to movie stardom after becoming famous as an "American Idol" contender two years ago. Hudson thanked her co-stars, who included Murphy, Jamie Foxx and Beyonce Knowles.

    "Because of you, I was able to work and learn from the best. Yes, you are the best," said Hudson, who added thanks to the actors guild. "Just thank you for noticing little old me and accepting me."

    The ensemble win for "Little Miss Sunshine" could give the film a best picture boost at the Oscars. But academy voters tend to favor heavy drama such as fellow nominees "Babel" and "The Departed."

    The guild category has never been a reliable forecast for how the top Oscar might play out. In the 11 years since the guild added the ensemble honor, only five winners have gone on to receive the best-picture Oscar, including 2005's "Crash."

    Past guild ensemble winners include "Sideways," "Gosford Park," "Apollo 13" and "The Birdcage," none of which won the best-picture Oscar.

    The guild's individual acting winners often line up with eventual Oscar, however. Three of the four guild winners for 2005 -- Philip Seymour Hoffman of "Capote," Reese Witherspoon of "Walk the Line" and Rachel Weisz of "The Constant Gardener" -- all went on to receive Oscars, while all four guild acting winners for 2004 won at the Oscars.

    Mirren's "Elizabeth I" co-star Jeremy Irons won the guild's prize for best actor in a TV movie or miniseries.

    Other TV winners were America Ferrera of "Ugly Betty" and Alec Baldwin of "30 Rock" as performers in comedy series, and Chandra Wilson of "Grey's Anatomy" and Hugh Laurie of "House" as performers in dramatic shows. TV ensemble prizes went to "Grey's Anatomy" for drama and "The Office" for comedy.

    (Agencies)