Disney

"My cousins took their 2 year old son to DisneyWorld a few years ago and commented that his favorite attractions were the ducks at the lake. So don't go with any pre-set notions of how your child will react to the parks. A fun time can be had by all, but remember that a toddler is a toddler and he's not going to care how much time and money you spent to bring him to DisneyWorld once he gets tired or hungry.

We stayed at one of the many off-site suite hotels and saved a bundle of money. The hotel had a shuttle that ran every half hour or so in the mornings and afternoons, and we used that to save ourselves the driving/parking hassles. But if your child is likely to need naps/downtime, you may be well-served by paying the extra $$$ for the on-site hotels, because it will save you at least a half-hour schlep each way.

Since you're spending all the time and money to get there, by all means stay a 3rd day. You won't run out of things to see and do, by any means. And keep in mind that you may spend hours or days going back to the same one or two things, because that is what makes your child happy."