We buy from Undercover Tourist using the Mousesavers.com newsletter link. The newsletter comes out the 15th of each month, and you have to sign up to receive it. It saves a few dollars over UT's prices, which are already lower than Disney's.
Other people have used Maple Leaf Tickets, Orlando Fun Tickets, and AAA. They all price a little differently and run different specials periodically, so you can check each website for the best deals on whatever tickets you want.
One other thought - if you book a package through Disney (like to get free dining), you have to buy at least a one day ticket. You won't save enough through the brokers to make that cost back, although you can save the one day ticket for another trip.
Our Authorized Disney Vacation Planners are here to provide personalized, expert advice, answer every question, and uncover the best discounts.
Let Dreams Unlimited Travel take care of all the details, so you can sit back, relax, and enjoy a stress-free vacation.