It seems many of us have the same feelings about how and when, and also realize that some things are not in our control.
Quickly, doing something I enjoy is a predominant theme. Supposedly, years back a retired military guy was running the Marine Corps marathon and had a heart attack near the Washington Monument in DC. According to the story, he was dead before he hit the ground. That is almost ideal -- almost because I'd rather land on grass and that area is mostly asphalt. Exercise and stay in good shape; as I understand it an athlete's heart attack can be much more final.
Checking yourself out is cheating, you lose by default. Just take enough Viagra and keep going after your 4 hours are up
Cremate me when it's over too. I don't want some archeologist digging me up 1000 years from now and putting my bones on exhibit in some museum, I'd rather be eaten by sharks and let them spread me across the ocean.