When my DD was a toddler, we took her to DL a lot and a couple of times to WDW. My DS is a toddler now.
Here are the attractions that they like:
IASW -- over and over and over again!
Playhouse Disney -- Bear in the Big Blue House
Buzz Lightyear -- DS loves it, DD not so much
Lion King Show
Pirates
Tom Sawyer's Island -- run off all that energy from the junk food treats
Bear Country Jamboree
Pooh
Transit something or other --- tomorrow land people mover
Energy at Epcot --- dinosaurs
Crush at Living Seas
The Living Land boat ride
The Jungle Cruise
The Swiss Family Robinson tree house
The cars (autopia)
Teacups -- don't spin (DD loved to spin as a toddler - DS not so much)
The fireworks shows --- Fantasmic may be a little too intense
Hope these suggestions are helpful. My DD really likes all rides, my DS is a little more hesitant.
Sorry I didn't categorize the list by park. I was just typing off the top of my head.
Good Luck!