If you'll be back again within a 365 day period, give serious consideration to an annual pass--particularly if you are a
DVC member and can get the AP discount.
Aside from that, the Magic Your Way pass would be the only other option. You just need to decide how many theme park days you want, and which options to purchase.
The park hopping option gives you the ability to go to different theme parks in one day and only use one day from your pass. For example you could go to the Magic Kingdom in the morning and Epcot at night. If you do not purchase the park hopping option, you can only enter one theme park per day. You can enter, leave, and return later to that same theme park, but you cannot go to different parks in a single day.
The plus pack gives you admission to the water parks, DisneyQuest or Pleasure Island. The number of admissions you get depends on the size of the MYW pass you buy.
Regarding the expiration, if you do not purchase the non-expiration option, the ticket expires 14 days after the first use.