When I stop and think about it, there are many things I've never done. Mission Space, any of the WS movies (other than China, did that once I think), any of the shows at HS (other than Indy - done that one a number of times), Dinosaur and Nemo at AK, Splash (I don't like getting wet on rides).
But each trip, we try to do something that we've never done. This upcoming trip, the plans are:
* 7DMR (new since our last trip)
* Meeting some of the Star Wars characters
* WS movies (at least some of them)
* Pandora rides