Sneak a Peek at InStyle's 'Celebrity Weddings'

Tom Cruise and Katie Holmes enjoyed a wedding fit for Italian royalty. There was a procession through the streets of Mexico for Ali Landry and filmmaker Alejandro Monteverde. And Marcia Cross and hubby Tom Mahoney opted for an elegant church ceremony.

"They announced us husband and wife, then we walked down the aisle," Marcia Cross recalled for "Extra" and InStyle. "Every picture of me was like, 'Ah, I was so happy!'"

After the intimate "I do's," guests at Marcia's wedding enjoyed a cool cocktail hour in an ultra-modern white room, inspired by the flower shop where the couple first met.

Then it was off to the reception for the couple's grand entrance.

"The reception was very colorful with lots of gorgeous flowers, and they were all sort of jewel toned, warm and passionate," Marcia revealed.

In Italy, Tom and Katie looked like royalty on their wedding day.

Now, fashion designer extraordinaire, Giorgio Armani, is inviting us inside his private studio and sharing secrets about TomKat's wedding designs.

Armani added just a hint of color -- a very dark blue -- to Tom's suit, while making sure Katie's dress was fit for a queen.

"It's a silk tulle, stretch, very functional," Giorgio dished.

"Extra" also got a sneak peak of Ali Landry and filmmaker Alejandro Monteverde just moments after they tied the knot in Mexico.

"It was very festive, very much a celebration," Landry shared.

Catch these beautiful brides and more when "InStyle Celebrity Weddings" airs Monday night on ABC.