I have taken my daughter to the
Disneyland Resort twice. At 7 months and at 15 months.
At those ages it really did not make a difference which park (and this was before bugs land was build). I think the most fun she had on her second trip was at DCA. The park was nearly deserted and we wandered into the farm area. Even though it was December, we let her play in the water a little bit. The farm area that my DH and I thought was TOTALLY lame was such and unexpected joy for her. Plus my husband fell in love with the Baby Center when he went to change her out of her wet clothes. The one at Disneyland is very nice, but frequently crowded. We had the run of the joint at DCA.
Sure there is much more for a 2-year-old to do in terms of rides that a 2-year-old can go on at Disneyland.... however if you are talking a Saturday, you might want to choose DCA because of the crowds.
Little kids can get a kick out of just about anything. My oldest is almost 4 now and just loves to ride the bus from long term parking at the airport. Just a huge smile on her face.
Also at DCA we kept running into characters where there was not a crowd to see them. She did not like the idea of going up to them... but loved to look at them from a good distance. The park was so empty, that even though we were standing back, Donald, Mickey and Max each at a different time walked over and gently tried to get my daughter to play with them. She would just bury her head into our bodies.
We are planning a trip in December with our two girls (will be 4-years and 20-months) and we think we will leave Disneyland when it gets crowded and enjoy DCA.