The actor is thrilled to be engaged to the "coolest girl in the world"

By Susan Mandel
October 12, 2007 08:00 AM

Jimmy Fallon is on cloud nine these days thanks to his recent engagement to Hollywood producer Nancy Juvonen.

“I’m just really excited right now and just happy. I’m the luckiest guy on earth,” the 33-year old actor tells PEOPLE. “She’s the coolest girl in the world.”

He was among the celebs who came to pay tribute to comedian Billy Crystal when he received this year’s Mark Twain Prize for American Humor at Washington, D.C.’s Kennedy Center on Thursday night.

Fallon and his bride-to-be haven’t picked a wedding date yet. “We’re still planning it,” he says. But “the sooner the better for me. I’m in love.”

Juvonen, 40, is Drew Barrymore‘s long-time business partner, and produced Fallon’s 2005 romantic comedy, Fever Pitch.

So was the former Saturday Night Live performer’s marriage proposal serious or funny? “It was serious. I did the whole one knee thing. I tried not to cry before she did. I was breaking down a little bit,” he says. “I don’t even remember what I said.”

Ironically, Fallon plays a man who’s commitment phobic in his new movie, Rockett, with Sharon Stone, Tom Arnold, and Lucy Liu, opening Nov. 20.

In real life though he doesn’t even want to miss out on the wedding planning. “Oh, I have to be [involved],” he says. “We’re trying to get a guest list together. But it’s all fun stuff. She’s a cool girl and it’s no stress at all.”

Joining Fallon in honoring Crystal at the Kennedy Center Thursday night were Robin Williams, Whoopi Goldberg, Barbara Walters, Danny DeVito, Robert DeNiro, Martin Short, Rob Reiner, Jon Lovitz, sportscaster Bob Costas, and New York Yankees manager Joe Torre. The show airs on PBS on Nov. 12 at 9 p.m. ET.