As a normal human I would say you would die instantly by the rein pin. The Mei freezing though, would be weird because of how fast your body is dropping. I think I painful death would be someone like Moira because she slowly drains the life out of you. I think it would be like getting tired, but who knows since I don’t know much about the lore.
Melted by molten core or Melted by sym turrets
Melt by Symmetra's Turret... Ugh don't really wanna imagine XD
Burning in lava isn’t as bad as getting your limbs slowly feasted on by wild dangerous animals
those torture devices they used back in the medevil times
Buried alive..starving..unable to move ..
Probably being set on fire, or drowning.
tracer screaming "cheers love the calvary's here!" at the top of her lungs and slicing your throat
Hearing Reaper standing behind you.