freezing is the best way to die after dying in your sleep. After you pass the first stage of pain you pretty much don't feel anything...
Burning is nasty...guess drowning too.
But the worst ways are man made...torture...chinese ones...SLOW ones.
here's one.
They tie you of 4 columns, paralel to the ground, and plant bamboo under you. bamboo grows straight 4-5 cm a day..about that. And it literally passes through you. Can you think of a slower death?
Ah, everyone is so cheerful these days!
The worst way to die is-
Having needles poked in your eyes while someone crushes your right testicles with high heels while someone pours maggots down your throat while someone rips out your tounges while some shoves a red hot poker up your arse and pulls your intestines out while someone shoves your intestines up your nose!
Hows that?
In Clive Cussler's book, Raise the Titanic,
when the ship is starting to go down, some nutty passenger who is protecting some chemical potion thingy makes a steward lock him in the vault with the chemical formula so it never falls into the wrong hands.
So here is this guy, locked in the vault in the Titanic, sinking two miles down into the Atlantic, slowly running out of air. Freaky or what ?