Hi, Elena! With the popularity of the Disney Dining Plan, many restaurants are booked to capacity daily. To make sure you get a table, make sure to make your Advance Dining Reservations by calling (407)WDW-DINE or online at
www.disneyworld.com. As of October 27, 2009, the booking window returns to 180 days.
So what are the most difficult reservations to get? It seems the number one is Le Cellier in Canada in Epcot. Close seconds include Cinderella's Royal Table, Mickey's Backyard BBQ, Princess Storybook Dining, and Chef Mickey's.
Not quite as bad, but call early: 50's Prime Time Cafe, Sci-Fi Dine-In Theatre, and Crystal Palace.
This does not mean you cannot get in! I just recommend being flexible. Schedule a late dinner or book at lunch time. There are cancellations, so try calling first thing in the morning to see if you can get a table. Once you have arrived at WDW, ask your resort concierge if there is any availability. They can check to see if anything has opened up.
Finally, try the walk-up! Let the cast member know you can come back later and are flexible, and they can sometimes fit you in. Good luck booking your Advance Dining Reservations!