My DD was sixteen months old on our first trip and she still loves the rides now that she most enjoyed then. I will mention now that she was terrified of the characters on that trip. She loved them and waved at them from a distance but, when they got close up she was very scared!
Well, her favourite in the MK was and still is Small World. Pirates of the Caribbean, Peter Pans Flight, Dumbo, Cinderellas Golden Carousel, Haunted Mansion, Country Bear Jamboree and the Pooh Bear ride are also great bets, as is Buzz Lightyear Space Ranger Spin. Donald Duck's Boat.
She loved lots of things in Epcot - the favourite being Spaceship Earth. She was also fascinated by the boat ride in the Land and the boat ride in Mexico. Plus, anywhere she could get wet - she really enjoyed!
MGM - the Great Movie Ride, the Little Mermaid, Backlot Tour, Bear in the Big Blue House.
AK: Legend of the Lion King, Kilimanjaro Safaris, the dig site and slides in Dinoland USA.
Everyone thought I was mad taking a 16 month old over to WDW all the way from the UK but, there is so much to see and do there - she never got bored. Have a great trip.