Piers Morgan on One-Year Anniversary, Favorite Guests and 'AGT'

The "Piers Morgan Tonight" host was welcomed to The Grove by "Extra's" Mario Lopez, and proudly spoke of his show's upcoming one-year anniversary. "We have a big line-up, it's gonna be fun," Morgan hinted, adding, "We've established ourselves as a show that people are aware of. We've had great guests."

Morgan revealed his favorite guest, saying, it "has to be Oprah," and "for sheer danger, Charlie Sheen at the height of his craziness. Walking in with five minutes to spare on live television on-air was madness, but brilliant."

The former "America's Got Talent" judge said he supported the show's pick for new judge Howard Stern. "It's gonna be fun. I am one of his biggest fans. I think he'll bring a whole new feel to the show."

Morgan continued, "I loved being the nice guy on the show, but in the end, especially in election year... being able to juggle both shows would've been too tricky. I had to chat with Simon [Cowell] and they agreed to let me off."

Catch "Piers Morgan Tonight's" one-year anniversary on Jan. 17, on CNN.