Out of all the park tickets... I find the best value one to be a 5 Park Orlando Flex.
This ticket will entitle you to 14 days of unlimited use to Universal Studios, Islands of Adventure, SeaWorld, Wet'n'Wild, and Busch Gardens.
If you love roller coasters and adrenalin pumping rides, miss out the Disney Parks and go for this ticket.
If you have got children under 10 with you, it is odds on that they will want to go and see the mouse. If this is the case, just buy a 1 day pass for Magic Kingdom, and then get the flex ticket for the rest of the time. At the parks above, they still have pleanty of childrens rides... and some great Big Kids Rides too.
Good luck with the trip!!!