1.) Food! We do the deluxe dining plan so that we can have all sorts of lovely meals without looking at the menu prices. We live in a town with very limited options for eating out, none of them better than just okay, and we don't eat out much at all in our day-to-day lives, so nice restaurants are a big part of any vacation for us.
2.) Resort. No offsite and no values, I want a hot tub to unwind in at the end of a long day in the parks and I don't want to have to drive to get there.
3.) Experiences. We've done BBB for DD, Pirate's League for both our older kids, the steam trains tour for DS, the Behind the Seeds tour for the whole family, and as the kids get older I'm sure we'll do more.
Really, travel itself is our splurge - we spend between 10-20% of our annual income on vacationing, and being able to do that is the biggest motivation for all my budgeting and cost-cutting at home. I'm sort of a minimalist when it comes to material possessions and the kids have picked up that attitude from me so we don't spend much on souvenirs or impulse items (like the glowing stuff during Wishes, the mister fans, etc) that end up as little more than clutter when we get home, but I'll happily spend on extra events/experiences that enhance our vacation and make memories.