Mine are not as deep or meaningful as you guys since I am very young, and havent started to experience anything near what you guys have, so these are going to sound stupid:

-Eat every major international food while IN the corresponding country (pizza in Italy, chinese in China, etc.)

-French kiss a hot french woman in France.

-Visit the most beautiful undiscovered spots in my country (Mexico), that arent swarmed with tourists.

-Skydive, or maybe even fly in a Glider.

-Visit Pompei, Athens, Rome, basically all those historical touristic hotspots.

-Visit all major Gothic Cathedrals.

-Visit Japan.

List goes on but the rest get personal, and really are dependant on alot of other things, while these I can definetly do as long as I live long enough.