Posted: Tue, 8 Jun 2010 04:56 PM - 10,146 Readers

By: Reagan Alexander and Scott Huver

In her first public appearance since the back-to-back news of her divorce and the adoption of her adorable baby son Louis, Sandra Bullock returned to the spotlight Saturday night, making a memorable surprise appearance at Spike TV's Guys Choice Awards.

There to accept the "Troops Choice" Award for Entertainer of the Year, from presenter Robert Downey, Jr. -- the honor was bestowed by members of the military -- the "Blind Side" Oscar winner, looking stunning in form-fitting black, leather mini-dress, received a standing ovation from the audience inside the Sony Pictures Studios in Los Angeles.

"Let's be honest here, just for a moment. We're all going to be honest, right?" Bullock, 45, told the crowd. "Did I win this for being entertainer of the year, or did I win this because of the spectacular I.E.D. [improvised explosive device] explosion that became my personal life?!"

Once the laughter subsided, she added, "No, it's okay. Because I would do it over again if it was to entertain our troops , and our extraordinary troops deserve something much more than some actress in a tight dress talking about herself."

She also told them, "I would sing, but you've seen enough pain in your lifetime. I would dance -- I'm a pretty good dancer, but as I mentioned, the dress is pretty tight."

America's Sweetheart

Members of the military stationed throughout the world were the only ones permitted to vote in the "Troops Choice" category, and did so via the Spike Web site. The crowd at the ceremony Saturday was made up of members of the U.S. Army, the U.S. Marine Corps and the U.S. Coast Guard, as well as such entertainment stars as Robert DeNiro, George Clooney, Leonardo DiCaprio, Scarlett Johansson, Jessica Biel, Bradley Cooper, Jon Hamm and others.

Bullock's appearance was kept secret from even the show's staff and participants, PEOPLE was told. U.S. Army 1st Sergeant Nicholas McClain, who shared the stage with Bullock, told PEOPLE afterward, "Originally we were told she wasn't going to be here at all, and somebody would be accepting on her behalf. So it was a great surprise to see her coming out on the stage."

The award went to Bullock, McClain, said, "Just because a lot of the movies that she does -- they provide different venues for everybody to see us. And we know that she has a lot of great support for the troops. And she's America's Sweetheart, regardless of anything that's been going on in her past."

As for sharing a stage with the Oscar winner, he said, "It was a great honor. She's a beautiful woman and a great supporter of the military."

The Guys Awards show will air June 20 on Spike TV.

Sunday night, Bullock is also scheduled to appear at the MTV Movie Awards, where she is to receive the Generation Award.

*  Story Contributed by: Reagan Alexander and Scott Huver