SanDestin.
New owner has built new new resorts and lots of new restaurants and shopping venues are available now.
There is a great "village" area with dining, live music nightly, good shopping that has also been expanded (doubled in size) over the past year or two.
There are shuttles that take you throughout the resort, bikes to rent, etc. . .
I have only been twice in off season (once in March, once this past September) but I highly recommend it.
Best part: my sister owns timeshare there and we go on 4 day getaways that are reasonable. From where we live it is only 5-6 hour drive so 4 days fit the bill perfectly.