The very sexy SIMON BAKER will feel right at home when he visits Ellen today -- he filmed some of his hit show, "The Mentalist," on Ellen's set! He's sure to bring a lovely thank-you gift for her.

As if the show couldn't get any sexier, CHRISTINA HENDRICKS is stopping by to talk about her breakout role on "Mad Men." Ellen wants to hear what it's like working alongside Jon Hamm!

BRUNO MARS has the #1 hit in the country, and he's here to perform it for Ellen. You don't want to miss him sing, "Just the Way You Are."