ummmm... well burning 你 would feel your flesh being heated away and being singed and I don't think that is a comfortable feeIing but drowning 你 would feel the water getting to 你 and the lack of air would be a very torturous feeling so I don't know. but are very slow ...
Neither is the best way to die. Slow painful deaths? are 你 crazy? I think, this is me 由 the way, that the best way to die would be in your sleep. No pain.
Neither of these are the best way to go...Other than dieing in your sleep I can't really think of another way that would hurt less 或者 even hurt at all.