Hi Telly,
When it comes to tickets, there are many, many options, and very few discounts. The biggest discount is for those who live in Florida. If you live in Florida, your best bet would be a Play 4 pass. If you don't live in Florida, then it depends on what you want to do in your 4 days. Do you want to only do the theme parks? And, if so, will you be wanting to do more than 1 theme park per day? If you only want to do the theme parks, and only 1 theme park per day, then your best bet would be the single tickets using the "Bounce Back" option (if that is still available). You would need to purchase those tickets when you get there at the gate, but they are restrictive type of tickets. Will you be wanting to do any other parks, such as a water park or Disney Quest? Will you be wanting to go to a theme park and a water park in the same day (on multiple days)? If yes, the the Ultimate Park Hopper would do the trick, otherwise it would probably not be worth it. Those are at the extremes. In between would be the Park Hopper and the Park Hopper Plus. Here are the advantages/disadvantages of each:
Single Day/Bounce Back: Each ticket can only be used in one theme park per day. Bounce Back tickets must be used within a certain time frame. Best for those who will not need "park hopper" feature.
Park Hopper: Minimum 4 days - good for all 4 theme parks for 4 (or 5) days. Does not have to be consecutive days, unused days never expire.
Park Hopper Plus: Minimum 5 days - same as Park Hopper, but with Flex features. Allows usage at Water Parks, Pleasure Island, Wide World of Sports. Flex features are not park hopper type. For instance, with Park Hopper Plus, you could go to Animal Kingdom and Epcot on same day and only use one day of pass. However, if you went to Typhoon Lagoon and then to River Country, you have used 2 flex features. Unused days/features never expire.
Annual Pass: Since you are only there for 4 days, you will probably not want this one. It is an Unlimited Park Hopper good for 1 year.
Premium Annual Pass: Unlimited Park Hopper pass good for 1 year.
Unlimited Park Hopper: Must be a Disney Resort guest to get this. Unlimited entry to all theme parks, water parks, Pleasure Island, Disney Quest, Wide World of Sports. Does not allow for entry to other special tickted events (Mickey's Very Merry Christmas Party for example).
About the only discount advice I can give would be to look into a Disney Club card. I love mine, but I also use it outside Disney World as well. Good luck on your trip and enjoy.