Infinite Time, Baby
Falling into a black hole the way I want to go out.
Not a small black hole, though. If you fall into one of those, your body will stretch into a thin line like a spaghetti noodle, and you'll die instantly. Instead, I want to be thrown into a supermassive black hole.
You can survive for much longer in a supermassive black hole, and what you'll see in the hours before your death will be incredible.
As I fall, I'll look up to the stars. Tens of millions, even billions of years will pass before me in an instant. If I die in a black hole, I'll be the last person to ever live, since time inside it passes so much slower than the outside. Who knows, you might be able to experience the entire age of the universe before you croak, watching stars explode and seeing space expand until there's total darkness, and then silence.
To me, that's the best ending I would ever be able to see, and that's why it's my go-to death sentence.