If you choose a park Hollywood Studios has great stuff for toddlers. They have the Playhouse Disney show plus all the the characters to meet and greet, Honey I shrunk the kids playground, little mermaid show, beauty and the beast show, Muppet Movie.
Downtown Disney would also be a fun place to go. They have the super fun water fountain near the christmas store. When my daughter was 2 she played in that fountain for over 2 hours (the water shoots out of the sidewalk). Just make sure to bring a change of clothes! They also have huge character statues all around the area that the kids can look at, touch etc. There is a small carousel & a train ride (i think). You can get ice cream at Ghirardelli, walk through the shops, get face painting, sit along the water, take a boat ride from DTD to the Port Orleans resort, go play on the PO playground and then take the boat ride back to DTD.