Go to Antarctica
It's one of the least understood, desolate, mysterious and beautiful places on Earth, and hardly anybody even thinks to travel there.

Submerge myself in a shark cage with great whites
I have always been fascinated with sharks, I never miss Shark Week on the Discovery Channel. The shark cage actually seems relatively safe, and seeing those things up close like that would be fantastic...and if they get me, I'm going to die anyway...might as well go with my bootstraps on! Fighting off a shark with my flipper.

I would take my whole family and close friends to a villa in Tuscany
We would all go somewhere amazing that we could just be together and nobody would have to go anywhere or do anything. We'd all stay in a big villa in Tuscany with a swimming pool and tons of rooms and books and a massive kitchen and a village nearby.

Write my will
It might not sound like a big deal, especially for someone with barely any assets. But I've got a relatively hefty life insurance policy...so I'd leave instructions for the funeral (no somber occasion, lots of flowers, friends, tell funny stories about me, etc.), as well as leave instructions for all my unpublished MS's.

climb an active volcano while it's erupting
I'd prob have to pull some strings with some vulcanologists, but I'd like to wear one of those flame retardant suits and go up toward the lava flow on Kilauea. SomIt would be cool to stand there and actually look at the forces in the center of the earth that shape the planet.