I would go to WDW. I never been to DL so I can't say much. Their is so much to do at WDW and DL. I would make a pro and cons lis of both places. We go to WDW because their are 4 Parks, and 2 water parks. So many resorts you can choose from.
Their are many events through out the year at WDW and I am sure DL have many events to. and Many places to Eat at.
Good Luck! Have Fun and Welcome.
Must do's in Magic Kingdom
Walt Disney World Railroad
Pirates of the Caribbean (great ride)
The Haunted Mansion
Splash Mountain
Big Thunder Mountain Railroad
Its a small world
Must do's in Epcot
Visit each country
We like to do Spaceship earth
Soarin (in the Land)
Maelstrom in Norway
May people like to eat in Canada at Le Cellier Steakhouse (I hope to try it on my next trip)
We like Rose and Crown Pub & Dining Room (in the UK)
Hollywood Studios
The Great Movie Ride
Star Tours
Lights,Motors,Action! Extreme Stunt Show
The Twilight Zone Tower of Terror (I am not a fan but I will try it again)
Rock 'n' Roller Coaster Starring Aerosmith
50's Prime Time Cafe (good food)
Animal Kingdom
Kilimanjaro Safaris
Kali River Rapids
Thier is also Downtown Disney and the 2 water Parks
I have only ever been to WDW because DL is so much further away from us. However, if I were going to do it all again and money wasn't an issue, I would experience DL first, since it was the original Walt creation. Then, of course, I'd plan a follow-up trip to WDW.